Show KCL backtraces (#7033)

* Add backtrace to errors

* Add display of backtraces with hints

* Change pane badge to only show count of errors

* Fix property name to not collide with Error superclass

* Increase min stack again

* Add e2e test that checks that the diagnostics are created in CodeMirror

* Remove unneeded code

* Change to the new hotness

.github/workflows/cargo-test.yml

@@ -88,6 +88,7 @@ jobs:
           KITTYCAD_API_TOKEN: ${{secrets.KITTYCAD_API_TOKEN_DEV}}
           ZOO_HOST: https://api.dev.zoo.dev
           RUST_BACKTRACE: full
+          RUST_MIN_STACK: 10485760000
       - name: Commit differences
         if: steps.path-changes.outputs.outside-kcl-samples == 'false' && steps.cargo-test-kcl-samples.outcome == 'failure'
         shell: bash
@@ -119,6 +120,7 @@ jobs:
           # Configure nextest when it's run by insta (via just).
           NEXTEST_PROFILE: ci
           RUST_BACKTRACE: full
+          RUST_MIN_STACK: 10485760000
       - name: Build and archive tests
         run: |
           cd rust
@@ -182,6 +184,7 @@ jobs:
         env:
           KITTYCAD_API_TOKEN: ${{secrets.KITTYCAD_API_TOKEN_DEV}}
           ZOO_HOST: https://api.dev.zoo.dev
+          RUST_MIN_STACK: 10485760000
       - name: Upload results
         if: always()
         run: .github/ci-cd-scripts/upload-results.sh
@@ -238,6 +241,7 @@ jobs:
           KITTYCAD_API_TOKEN: ${{secrets.KITTYCAD_API_TOKEN_DEV}}
           ZOO_HOST: https://api.dev.zoo.dev
           MODELING_APP_INTERNAL_SAMPLES_SECRET: ${{secrets.MODELING_APP_INTERNAL_SAMPLES_SECRET}}
+          RUST_MIN_STACK: 10485760000
   run-wasm-tests:
     name: Run wasm tests
     strategy:

e2e/playwright/code-pane-and-errors.spec.ts

@@ -235,6 +235,48 @@ extrude001 = extrude(sketch001, length = 5)`
         .first()
     ).toBeVisible()
   })
+
+  test('KCL errors with functions show hints for the entire backtrace', async ({
+    page,
+    homePage,
+    scene,
+    cmdBar,
+    editor,
+    toolbar,
+  }) => {
+    await homePage.goToModelingScene()
+    await scene.settled(cmdBar)
+
+    const code = `fn check(@x) {
+  return assert(x, isGreaterThan = 0)
+}
+
+fn middle(@x) {
+  return check(x)
+}
+
+middle(1)
+middle(0)
+`
+    await test.step('Set the code with a KCL error', async () => {
+      await toolbar.openPane('code')
+      await editor.replaceCode('', code)
+    })
+    // This shows all the diagnostics in a way that doesn't require the mouse
+    // pointer hovering over a coordinate, which would be brittle.
+    await test.step('Open CodeMirror diagnostics list', async () => {
+      // Ensure keyboard focus is in the editor.
+      await page.getByText('fn check(').click()
+      await page.keyboard.press('ControlOrMeta+Shift+M')
+    })
+    await expect(
+      page.getByText(`assert failed: Expected 0 to be greater than 0 but it wasn't
+check()
+middle()`)
+    ).toBeVisible()
+    // There should be one hint inside middle() and one at the top level.
+    await expect(page.getByText('Part of the error backtrace')).toHaveCount(2)
+  })
 })
 
 test(

rust/kcl-lib/e2e/executor/main.rs

@@ -2,7 +2,7 @@ mod cache;
 
 use kcl_lib::{
     test_server::{execute_and_export_step, execute_and_snapshot, execute_and_snapshot_no_auth},
-    ExecError,
+    BacktraceItem, ExecError, ModuleId, SourceRange,
 };
 
 /// The minimum permissible difference between asserted twenty-twenty images.
@@ -441,10 +441,15 @@ async fn kcl_test_import_file_doesnt_exist() {
 model = cube"#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "File `thing.obj` does not exist.");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"semantic: KclErrorDetails { source_ranges: [SourceRange([0, 18, 0])], message: "File `thing.obj` does not exist." }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(0, 18, ModuleId::default()),
+            fn_name: None,
+        }]
     );
 }
 
@@ -519,10 +524,18 @@ import 'e2e/executor/inputs/cube.gltf'
 model = cube"#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"semantic: KclErrorDetails { source_ranges: [SourceRange([32, 70, 0])], message: "The given format does not match the file extension. Expected: `gltf`, Given: `obj`" }"#
+        err.message(),
+        "The given format does not match the file extension. Expected: `gltf`, Given: `obj`"
+    );
+    assert_eq!(
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(32, 70, ModuleId::default()),
+            fn_name: None,
+        }]
     );
 }
 
@@ -1666,10 +1679,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have an x constrained angle of 90 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([70, 111, 0])], message: "Cannot have an x constrained angle of 90 degrees" }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(70, 111, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1686,10 +1704,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have an x constrained angle of 270 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([70, 112, 0])], message: "Cannot have an x constrained angle of 270 degrees" }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(70, 112, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1706,10 +1729,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 0 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([70, 110, 0])], message: "Cannot have a y constrained angle of 0 degrees" }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(70, 110, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1726,10 +1754,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 180 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([70, 112, 0])], message: "Cannot have a y constrained angle of 180 degrees" }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(70, 112, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1746,10 +1779,15 @@ extrusion = extrude(sketch001, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have an x constrained angle of 90 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([66, 116, 0])], message: "Cannot have an x constrained angle of 90 degrees" }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(66, 116, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1757,7 +1795,7 @@ extrusion = extrude(sketch001, length = 10)
 async fn kcl_test_angled_line_of_x_length_270() {
     let code = r#"sketch001 = startSketchOn(XZ)
   |> startProfile(at = [0, 0])
-  |> angledLine(angle = 90, lengthX = 90, tag = $edge1)
+  |> angledLine(angle = 270, lengthX = 90, tag = $edge1)
   |> angledLine(angle = -15, lengthX = -15, tag = $edge2)
   |> line(end = [0, -5])
   |> close(tag = $edge3)
@@ -1766,10 +1804,15 @@ extrusion = extrude(sketch001, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have an x constrained angle of 270 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([66, 116, 0])], message: "Cannot have an x constrained angle of 90 degrees" }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(66, 117, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1788,10 +1831,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 0 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([95, 130, 0])], message: "Cannot have a y constrained angle of 0 degrees" }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(95, 130, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1810,10 +1858,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 180 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([95, 132, 0])], message: "Cannot have a y constrained angle of 180 degrees" }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(95, 132, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1832,10 +1885,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 180 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([95, 133, 0])], message: "Cannot have a y constrained angle of 180 degrees" }"#
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(95, 133, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1849,10 +1907,31 @@ someFunction('INVALID')
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
     assert_eq!(
-        result.err().unwrap().to_string(),
-        r#"semantic: KclErrorDetails { source_ranges: [SourceRange([46, 55, 0]), SourceRange([60, 83, 0])], message: "This function expected the input argument to be Solid or Plane but it's actually of type string" }"#
+        err.message(),
+        "This function expected the input argument to be Solid or Plane but it's actually of type string"
+    );
+    assert_eq!(
+        err.source_ranges(),
+        vec![
+            SourceRange::new(46, 55, ModuleId::default()),
+            SourceRange::new(60, 83, ModuleId::default()),
+        ]
+    );
+    assert_eq!(
+        err.backtrace(),
+        vec![
+            BacktraceItem {
+                source_range: SourceRange::new(46, 55, ModuleId::default()),
+                fn_name: Some("someFunction".to_owned()),
+            },
+            BacktraceItem {
+                source_range: SourceRange::new(60, 83, ModuleId::default()),
+                fn_name: None,
+            },
+        ]
     );
 }
 
@@ -1873,12 +1952,14 @@ async fn kcl_test_error_no_auth_websocket() {
 "#;
 
     let result = execute_and_snapshot_no_auth(code, None).await;
-    assert!(result.is_err());
-    assert!(result
-        .err()
-        .unwrap()
-        .to_string()
-        .contains("Please send the following object over this websocket"));
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert!(
+        err.message()
+            .contains("Please send the following object over this websocket"),
+        "actual: {}",
+        err.message()
+    );
 }
 
 #[tokio::test(flavor = "multi_thread")]

rust/kcl-lib/src/engine/conn.rs

@@ -439,12 +439,7 @@ impl EngineManager for EngineConnection {
                 request_sent: tx,
             })
             .await
-            .map_err(|e| {
-                KclError::Engine(KclErrorDetails {
-                    message: format!("Failed to send debug: {}", e),
-                    source_ranges: vec![],
-                })
-            })?;
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(format!("Failed to send debug: {}", e), vec![])))?;
 
         let _ = rx.await;
         Ok(())
@@ -479,25 +474,25 @@ impl EngineManager for EngineConnection {
             })
             .await
             .map_err(|e| {
-                KclError::Engine(KclErrorDetails {
-                    message: format!("Failed to send modeling command: {}", e),
-                    source_ranges: vec![source_range],
-                })
+                KclError::Engine(KclErrorDetails::new(
+                    format!("Failed to send modeling command: {}", e),
+                    vec![source_range],
+                ))
             })?;
 
         // Wait for the request to be sent.
         rx.await
             .map_err(|e| {
-                KclError::Engine(KclErrorDetails {
-                    message: format!("could not send request to the engine actor: {e}"),
-                    source_ranges: vec![source_range],
-                })
+                KclError::Engine(KclErrorDetails::new(
+                    format!("could not send request to the engine actor: {e}"),
+                    vec![source_range],
+                ))
             })?
             .map_err(|e| {
-                KclError::Engine(KclErrorDetails {
-                    message: format!("could not send request to the engine: {e}"),
-                    source_ranges: vec![source_range],
-                })
+                KclError::Engine(KclErrorDetails::new(
+                    format!("could not send request to the engine: {e}"),
+                    vec![source_range],
+                ))
             })?;
 
         Ok(())
@@ -521,15 +516,15 @@ impl EngineManager for EngineConnection {
                 // Check if we have any pending errors.
                 let pe = self.pending_errors.read().await;
                 if !pe.is_empty() {
-                    return Err(KclError::Engine(KclErrorDetails {
-                        message: pe.join(", ").to_string(),
-                        source_ranges: vec![source_range],
-                    }));
+                    return Err(KclError::Engine(KclErrorDetails::new(
+                        pe.join(", ").to_string(),
+                        vec![source_range],
+                    )));
                 } else {
-                    return Err(KclError::Engine(KclErrorDetails {
-                        message: "Modeling command failed: websocket closed early".to_string(),
-                        source_ranges: vec![source_range],
-                    }));
+                    return Err(KclError::Engine(KclErrorDetails::new(
+                        "Modeling command failed: websocket closed early".to_string(),
+                        vec![source_range],
+                    )));
                 }
             }
 
@@ -548,10 +543,10 @@ impl EngineManager for EngineConnection {
             }
         }
 
-        Err(KclError::Engine(KclErrorDetails {
-            message: format!("Modeling command timed out `{}`", id),
-            source_ranges: vec![source_range],
-        }))
+        Err(KclError::Engine(KclErrorDetails::new(
+            format!("Modeling command timed out `{}`", id),
+            vec![source_range],
+        )))
     }
 
     async fn get_session_data(&self) -> Option<ModelingSessionData> {

rust/kcl-lib/src/engine/conn_wasm.rs

@@ -147,32 +147,27 @@ impl EngineConnection {
         id_to_source_range: HashMap<uuid::Uuid, SourceRange>,
     ) -> Result<(), KclError> {
         let source_range_str = serde_json::to_string(&source_range).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to serialize source range: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to serialize source range: {:?}", e),
+                vec![source_range],
+            ))
         })?;
         let cmd_str = serde_json::to_string(&cmd).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to serialize modeling command: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to serialize modeling command: {:?}", e),
+                vec![source_range],
+            ))
         })?;
         let id_to_source_range_str = serde_json::to_string(&id_to_source_range).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to serialize id to source range: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to serialize id to source range: {:?}", e),
+                vec![source_range],
+            ))
         })?;
 
         self.manager
             .fire_modeling_cmd_from_wasm(id.to_string(), source_range_str, cmd_str, id_to_source_range_str)
-            .map_err(|e| {
-                KclError::Engine(KclErrorDetails {
-                    message: e.to_string().into(),
-                    source_ranges: vec![source_range],
-                })
-            })?;
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
 
         Ok(())
     }
@@ -185,33 +180,28 @@ impl EngineConnection {
         id_to_source_range: HashMap<uuid::Uuid, SourceRange>,
     ) -> Result<WebSocketResponse, KclError> {
         let source_range_str = serde_json::to_string(&source_range).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to serialize source range: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to serialize source range: {:?}", e),
+                vec![source_range],
+            ))
         })?;
         let cmd_str = serde_json::to_string(&cmd).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to serialize modeling command: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to serialize modeling command: {:?}", e),
+                vec![source_range],
+            ))
         })?;
         let id_to_source_range_str = serde_json::to_string(&id_to_source_range).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to serialize id to source range: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to serialize id to source range: {:?}", e),
+                vec![source_range],
+            ))
         })?;
 
         let promise = self
             .manager
             .send_modeling_cmd_from_wasm(id.to_string(), source_range_str, cmd_str, id_to_source_range_str)
-            .map_err(|e| {
-                KclError::Engine(KclErrorDetails {
-                    message: e.to_string().into(),
-                    source_ranges: vec![source_range],
-                })
-            })?;
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
 
         let value = crate::wasm::JsFuture::from(promise).await.map_err(|e| {
             // Try to parse the error as an engine error.
@@ -219,53 +209,52 @@ impl EngineConnection {
             if let Ok(kittycad_modeling_cmds::websocket::FailureWebSocketResponse { errors, .. }) =
                 serde_json::from_str(&err_str)
             {
-                KclError::Engine(KclErrorDetails {
-                    message: errors.iter().map(|e| e.message.clone()).collect::<Vec<_>>().join("\n"),
-                    source_ranges: vec![source_range],
-                })
+                KclError::Engine(KclErrorDetails::new(
+                    errors.iter().map(|e| e.message.clone()).collect::<Vec<_>>().join("\n"),
+                    vec![source_range],
+                ))
             } else if let Ok(data) =
                 serde_json::from_str::<Vec<kittycad_modeling_cmds::websocket::FailureWebSocketResponse>>(&err_str)
             {
                 if let Some(data) = data.first() {
                     // It could also be an array of responses.
-                    KclError::Engine(KclErrorDetails {
-                        message: data
-                            .errors
+                    KclError::Engine(KclErrorDetails::new(
+                        data.errors
                             .iter()
                             .map(|e| e.message.clone())
                             .collect::<Vec<_>>()
                             .join("\n"),
-                        source_ranges: vec![source_range],
-                    })
+                        vec![source_range],
+                    ))
                 } else {
-                    KclError::Engine(KclErrorDetails {
-                        message: "Received empty response from engine".into(),
-                        source_ranges: vec![source_range],
-                    })
+                    KclError::Engine(KclErrorDetails::new(
+                        "Received empty response from engine".into(),
+                        vec![source_range],
+                    ))
                 }
             } else {
-                KclError::Engine(KclErrorDetails {
-                    message: format!("Failed to wait for promise from send modeling command: {:?}", e),
-                    source_ranges: vec![source_range],
-                })
+                KclError::Engine(KclErrorDetails::new(
+                    format!("Failed to wait for promise from send modeling command: {:?}", e),
+                    vec![source_range],
+                ))
             }
         })?;
 
         if value.is_null() || value.is_undefined() {
-            return Err(KclError::Engine(KclErrorDetails {
-                message: "Received null or undefined response from engine".into(),
-                source_ranges: vec![source_range],
-            }));
+            return Err(KclError::Engine(KclErrorDetails::new(
+                "Received null or undefined response from engine".into(),
+                vec![source_range],
+            )));
         }
 
         // Convert JsValue to a Uint8Array
         let data = js_sys::Uint8Array::from(value);
 
         let ws_result: WebSocketResponse = bson::from_slice(&data.to_vec()).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to deserialize bson response from engine: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to deserialize bson response from engine: {:?}", e),
+                vec![source_range],
+            ))
         })?;
 
         Ok(ws_result)
@@ -316,18 +305,16 @@ impl crate::engine::EngineManager for EngineConnection {
         *self.default_planes.write().await = Some(new_planes);
 
         // Start a new session.
-        let promise = self.manager.start_new_session().map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: e.to_string().into(),
-                source_ranges: vec![source_range],
-            })
-        })?;
+        let promise = self
+            .manager
+            .start_new_session()
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
 
         crate::wasm::JsFuture::from(promise).await.map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to wait for promise from start new session: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to wait for promise from start new session: {:?}", e),
+                vec![source_range],
+            ))
         })?;
 
         Ok(())

rust/kcl-lib/src/engine/mod.rs

@@ -276,10 +276,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                 {
                     let duration = instant::Duration::from_millis(1);
                     wasm_timer::Delay::new(duration).await.map_err(|err| {
-                        KclError::Internal(KclErrorDetails {
-                            message: format!("Failed to sleep: {:?}", err),
-                            source_ranges: vec![source_range],
-                        })
+                        KclError::Internal(KclErrorDetails::new(
+                            format!("Failed to sleep: {:?}", err),
+                            vec![source_range],
+                        ))
                     })?;
                 }
                 #[cfg(not(target_arch = "wasm32"))]
@@ -293,10 +293,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
             return Ok(response);
         }
 
-        Err(KclError::Engine(KclErrorDetails {
-            message: "async command timed out".to_string(),
-            source_ranges: vec![source_range],
-        }))
+        Err(KclError::Engine(KclErrorDetails::new(
+            "async command timed out".to_string(),
+            vec![source_range],
+        )))
     }
 
     /// Ensure ALL async commands have been completed.
@@ -547,10 +547,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                     id_to_source_range.insert(Uuid::from(*cmd_id), *range);
                 }
                 _ => {
-                    return Err(KclError::Engine(KclErrorDetails {
-                        message: format!("The request is not a modeling command: {:?}", req),
-                        source_ranges: vec![*range],
-                    }));
+                    return Err(KclError::Engine(KclErrorDetails::new(
+                        format!("The request is not a modeling command: {:?}", req),
+                        vec![*range],
+                    )));
                 }
             }
         }
@@ -595,10 +595,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                     self.parse_batch_responses(last_id.into(), id_to_source_range, responses)
                 } else {
                     // We should never get here.
-                    Err(KclError::Engine(KclErrorDetails {
-                        message: format!("Failed to get batch response: {:?}", response),
-                        source_ranges: vec![source_range],
-                    }))
+                    Err(KclError::Engine(KclErrorDetails::new(
+                        format!("Failed to get batch response: {:?}", response),
+                        vec![source_range],
+                    )))
                 }
             }
             WebSocketRequest::ModelingCmdReq(ModelingCmdReq { cmd: _, cmd_id }) => {
@@ -610,20 +610,20 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                 // request so we need the original request source range in case the engine returns
                 // an error.
                 let source_range = id_to_source_range.get(cmd_id.as_ref()).cloned().ok_or_else(|| {
-                    KclError::Engine(KclErrorDetails {
-                        message: format!("Failed to get source range for command ID: {:?}", cmd_id),
-                        source_ranges: vec![],
-                    })
+                    KclError::Engine(KclErrorDetails::new(
+                        format!("Failed to get source range for command ID: {:?}", cmd_id),
+                        vec![],
+                    ))
                 })?;
                 let ws_resp = self
                     .inner_send_modeling_cmd(cmd_id.into(), source_range, final_req, id_to_source_range)
                     .await?;
                 self.parse_websocket_response(ws_resp, source_range)
             }
-            _ => Err(KclError::Engine(KclErrorDetails {
-                message: format!("The final request is not a modeling command: {:?}", final_req),
-                source_ranges: vec![source_range],
-            })),
+            _ => Err(KclError::Engine(KclErrorDetails::new(
+                format!("The final request is not a modeling command: {:?}", final_req),
+                vec![source_range],
+            ))),
         }
     }
 
@@ -729,10 +729,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
         for (name, plane_id, color) in plane_settings {
             let info = DEFAULT_PLANE_INFO.get(&name).ok_or_else(|| {
                 // We should never get here.
-                KclError::Engine(KclErrorDetails {
-                    message: format!("Failed to get default plane info for: {:?}", name),
-                    source_ranges: vec![source_range],
-                })
+                KclError::Engine(KclErrorDetails::new(
+                    format!("Failed to get default plane info for: {:?}", name),
+                    vec![source_range],
+                ))
             })?;
             planes.insert(
                 name,
@@ -763,15 +763,14 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
             WebSocketResponse::Success(success) => Ok(success.resp),
             WebSocketResponse::Failure(fail) => {
                 let _request_id = fail.request_id;
-                Err(KclError::Engine(KclErrorDetails {
-                    message: fail
-                        .errors
+                Err(KclError::Engine(KclErrorDetails::new(
+                    fail.errors
                         .iter()
                         .map(|e| e.message.clone())
                         .collect::<Vec<_>>()
                         .join("\n"),
-                    source_ranges: vec![source_range],
-                }))
+                    vec![source_range],
+                )))
             }
         }
     }
@@ -806,25 +805,25 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                 BatchResponse::Failure { errors } => {
                     // Get the source range for the command.
                     let source_range = id_to_source_range.get(cmd_id).cloned().ok_or_else(|| {
-                        KclError::Engine(KclErrorDetails {
-                            message: format!("Failed to get source range for command ID: {:?}", cmd_id),
-                            source_ranges: vec![],
-                        })
+                        KclError::Engine(KclErrorDetails::new(
+                            format!("Failed to get source range for command ID: {:?}", cmd_id),
+                            vec![],
+                        ))
                     })?;
-                    return Err(KclError::Engine(KclErrorDetails {
-                        message: errors.iter().map(|e| e.message.clone()).collect::<Vec<_>>().join("\n"),
-                        source_ranges: vec![source_range],
-                    }));
+                    return Err(KclError::Engine(KclErrorDetails::new(
+                        errors.iter().map(|e| e.message.clone()).collect::<Vec<_>>().join("\n"),
+                        vec![source_range],
+                    )));
                 }
             }
         }
 
         // Return an error that we did not get an error or the response we wanted.
         // This should never happen but who knows.
-        Err(KclError::Engine(KclErrorDetails {
-            message: format!("Failed to find response for command ID: {:?}", id),
-            source_ranges: vec![],
-        }))
+        Err(KclError::Engine(KclErrorDetails::new(
+            format!("Failed to find response for command ID: {:?}", id),
+            vec![],
+        )))
     }
 
     async fn modify_grid(

rust/kcl-lib/src/errors.rs

@@ -380,20 +380,39 @@ impl miette::Diagnostic for Report {
 }
 
 #[derive(Debug, Serialize, Deserialize, ts_rs::TS, Clone, PartialEq, Eq, thiserror::Error, miette::Diagnostic)]
+#[serde(rename_all = "camelCase")]
 #[error("{message}")]
 #[ts(export)]
 pub struct KclErrorDetails {
-    #[serde(rename = "sourceRanges")]
     #[label(collection, "Errors")]
     pub source_ranges: Vec<SourceRange>,
+    pub backtrace: Vec<BacktraceItem>,
     #[serde(rename = "msg")]
     pub message: String,
 }
 
+impl KclErrorDetails {
+    pub fn new(message: String, source_ranges: Vec<SourceRange>) -> KclErrorDetails {
+        let backtrace = source_ranges
+            .iter()
+            .map(|s| BacktraceItem {
+                source_range: *s,
+                fn_name: None,
+            })
+            .collect();
+        KclErrorDetails {
+            source_ranges,
+            backtrace,
+            message,
+        }
+    }
+}
+
 impl KclError {
     pub fn internal(message: String) -> KclError {
         KclError::Internal(KclErrorDetails {
             source_ranges: Default::default(),
+            backtrace: Default::default(),
             message,
         })
     }
@@ -455,45 +474,122 @@ impl KclError {
         }
     }
 
+    pub fn backtrace(&self) -> Vec<BacktraceItem> {
+        match self {
+            KclError::Lexical(e)
+            | KclError::Syntax(e)
+            | KclError::Semantic(e)
+            | KclError::ImportCycle(e)
+            | KclError::Type(e)
+            | KclError::Io(e)
+            | KclError::Unexpected(e)
+            | KclError::ValueAlreadyDefined(e)
+            | KclError::UndefinedValue(e)
+            | KclError::InvalidExpression(e)
+            | KclError::Engine(e)
+            | KclError::Internal(e) => e.backtrace.clone(),
+        }
+    }
+
     pub(crate) fn override_source_ranges(&self, source_ranges: Vec<SourceRange>) -> Self {
         let mut new = self.clone();
         match &mut new {
-            KclError::Lexical(e) => e.source_ranges = source_ranges,
-            KclError::Syntax(e) => e.source_ranges = source_ranges,
-            KclError::Semantic(e) => e.source_ranges = source_ranges,
-            KclError::ImportCycle(e) => e.source_ranges = source_ranges,
-            KclError::Type(e) => e.source_ranges = source_ranges,
-            KclError::Io(e) => e.source_ranges = source_ranges,
-            KclError::Unexpected(e) => e.source_ranges = source_ranges,
-            KclError::ValueAlreadyDefined(e) => e.source_ranges = source_ranges,
-            KclError::UndefinedValue(e) => e.source_ranges = source_ranges,
-            KclError::InvalidExpression(e) => e.source_ranges = source_ranges,
-            KclError::Engine(e) => e.source_ranges = source_ranges,
-            KclError::Internal(e) => e.source_ranges = source_ranges,
+            KclError::Lexical(e)
+            | KclError::Syntax(e)
+            | KclError::Semantic(e)
+            | KclError::ImportCycle(e)
+            | KclError::Type(e)
+            | KclError::Io(e)
+            | KclError::Unexpected(e)
+            | KclError::ValueAlreadyDefined(e)
+            | KclError::UndefinedValue(e)
+            | KclError::InvalidExpression(e)
+            | KclError::Engine(e)
+            | KclError::Internal(e) => {
+                e.backtrace = source_ranges
+                    .iter()
+                    .map(|s| BacktraceItem {
+                        source_range: *s,
+                        fn_name: None,
+                    })
+                    .collect();
+                e.source_ranges = source_ranges;
+            }
         }
 
         new
     }
 
-    pub(crate) fn add_source_ranges(&self, source_ranges: Vec<SourceRange>) -> Self {
+    pub(crate) fn set_last_backtrace_fn_name(&self, last_fn_name: Option<String>) -> Self {
         let mut new = self.clone();
         match &mut new {
-            KclError::Lexical(e) => e.source_ranges.extend(source_ranges),
-            KclError::Syntax(e) => e.source_ranges.extend(source_ranges),
-            KclError::Semantic(e) => e.source_ranges.extend(source_ranges),
-            KclError::ImportCycle(e) => e.source_ranges.extend(source_ranges),
-            KclError::Type(e) => e.source_ranges.extend(source_ranges),
-            KclError::Io(e) => e.source_ranges.extend(source_ranges),
-            KclError::Unexpected(e) => e.source_ranges.extend(source_ranges),
-            KclError::ValueAlreadyDefined(e) => e.source_ranges.extend(source_ranges),
-            KclError::UndefinedValue(e) => e.source_ranges.extend(source_ranges),
-            KclError::InvalidExpression(e) => e.source_ranges.extend(source_ranges),
-            KclError::Engine(e) => e.source_ranges.extend(source_ranges),
-            KclError::Internal(e) => e.source_ranges.extend(source_ranges),
+            KclError::Lexical(e)
+            | KclError::Syntax(e)
+            | KclError::Semantic(e)
+            | KclError::ImportCycle(e)
+            | KclError::Type(e)
+            | KclError::Io(e)
+            | KclError::Unexpected(e)
+            | KclError::ValueAlreadyDefined(e)
+            | KclError::UndefinedValue(e)
+            | KclError::InvalidExpression(e)
+            | KclError::Engine(e)
+            | KclError::Internal(e) => {
+                if let Some(item) = e.backtrace.last_mut() {
+                    item.fn_name = last_fn_name;
+                }
+            }
         }
 
         new
     }
+
+    pub(crate) fn add_unwind_location(&self, last_fn_name: Option<String>, source_range: SourceRange) -> Self {
+        let mut new = self.clone();
+        match &mut new {
+            KclError::Lexical(e)
+            | KclError::Syntax(e)
+            | KclError::Semantic(e)
+            | KclError::ImportCycle(e)
+            | KclError::Type(e)
+            | KclError::Io(e)
+            | KclError::Unexpected(e)
+            | KclError::ValueAlreadyDefined(e)
+            | KclError::UndefinedValue(e)
+            | KclError::InvalidExpression(e)
+            | KclError::Engine(e)
+            | KclError::Internal(e) => {
+                if let Some(item) = e.backtrace.last_mut() {
+                    item.fn_name = last_fn_name;
+                }
+                e.backtrace.push(BacktraceItem {
+                    source_range,
+                    fn_name: None,
+                });
+                e.source_ranges.push(source_range);
+            }
+        }
+
+        new
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, ts_rs::TS, thiserror::Error, miette::Diagnostic)]
+#[serde(rename_all = "camelCase")]
+#[ts(export)]
+pub struct BacktraceItem {
+    pub source_range: SourceRange,
+    pub fn_name: Option<String>,
+}
+
+impl std::fmt::Display for BacktraceItem {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if let Some(fn_name) = &self.fn_name {
+            write!(f, "{fn_name}: {:?}", self.source_range)
+        } else {
+            write!(f, "(fn): {:?}", self.source_range)
+        }
+    }
 }
 
 impl IntoDiagnostic for KclError {
@@ -551,6 +647,7 @@ impl From<pyo3::PyErr> for KclError {
     fn from(error: pyo3::PyErr) -> Self {
         KclError::Internal(KclErrorDetails {
             source_ranges: vec![],
+            backtrace: Default::default(),
             message: error.to_string(),
         })
     }
@@ -629,8 +726,13 @@ impl CompilationError {
 
 impl From<CompilationError> for KclErrorDetails {
     fn from(err: CompilationError) -> Self {
+        let backtrace = vec![BacktraceItem {
+            source_range: err.source_range,
+            fn_name: None,
+        }];
         KclErrorDetails {
             source_ranges: vec![err.source_range],
+            backtrace,
             message: err.message,
         }
     }

rust/kcl-lib/src/execution/annotations.rs

@@ -70,10 +70,10 @@ pub(super) fn expect_properties<'a>(
 ) -> Result<&'a [Node<ObjectProperty>], KclError> {
     assert_eq!(annotation.name().unwrap(), for_key);
     Ok(&**annotation.properties.as_ref().ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
-            message: format!("Empty `{for_key}` annotation"),
-            source_ranges: vec![annotation.as_source_range()],
-        })
+        KclError::Semantic(KclErrorDetails::new(
+            format!("Empty `{for_key}` annotation"),
+            vec![annotation.as_source_range()],
+        ))
     })?)
 }
 
@@ -84,10 +84,10 @@ pub(super) fn expect_ident(expr: &Expr) -> Result<&str, KclError> {
         }
     }
 
-    Err(KclError::Semantic(KclErrorDetails {
-        message: "Unexpected settings value, expected a simple name, e.g., `mm`".to_owned(),
-        source_ranges: vec![expr.into()],
-    }))
+    Err(KclError::Semantic(KclErrorDetails::new(
+        "Unexpected settings value, expected a simple name, e.g., `mm`".to_owned(),
+        vec![expr.into()],
+    )))
 }
 
 // Returns the unparsed number literal.
@@ -98,10 +98,10 @@ pub(super) fn expect_number(expr: &Expr) -> Result<String, KclError> {
         }
     }
 
-    Err(KclError::Semantic(KclErrorDetails {
-        message: "Unexpected settings value, expected a number, e.g., `1.0`".to_owned(),
-        source_ranges: vec![expr.into()],
-    }))
+    Err(KclError::Semantic(KclErrorDetails::new(
+        "Unexpected settings value, expected a number, e.g., `1.0`".to_owned(),
+        vec![expr.into()],
+    )))
 }
 
 pub(super) fn get_impl(annotations: &[Node<Annotation>], source_range: SourceRange) -> Result<Option<Impl>, KclError> {
@@ -113,14 +113,14 @@ pub(super) fn get_impl(annotations: &[Node<Annotation>], source_range: SourceRan
             if &*p.key.name == IMPL {
                 if let Some(s) = p.value.ident_name() {
                     return Impl::from_str(s).map(Some).map_err(|_| {
-                        KclError::Semantic(KclErrorDetails {
-                            message: format!(
+                        KclError::Semantic(KclErrorDetails::new(
+                            format!(
                                 "Invalid value for {} attribute, expected one of: {}",
                                 IMPL,
                                 IMPL_VALUES.join(", ")
                             ),
-                            source_ranges: vec![source_range],
-                        })
+                            vec![source_range],
+                        ))
                     });
                 }
             }
@@ -139,12 +139,12 @@ impl UnitLen {
             "inch" | "in" => Ok(UnitLen::Inches),
             "ft" => Ok(UnitLen::Feet),
             "yd" => Ok(UnitLen::Yards),
-            value => Err(KclError::Semantic(KclErrorDetails {
-                message: format!(
+            value => Err(KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "Unexpected value for length units: `{value}`; expected one of `mm`, `cm`, `m`, `in`, `ft`, `yd`"
                 ),
-                source_ranges: vec![source_range],
-            })),
+                vec![source_range],
+            ))),
         }
     }
 }
@@ -154,10 +154,10 @@ impl UnitAngle {
         match s {
             "deg" => Ok(UnitAngle::Degrees),
             "rad" => Ok(UnitAngle::Radians),
-            value => Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Unexpected value for angle units: `{value}`; expected one of `deg`, `rad`"),
-                source_ranges: vec![source_range],
-            })),
+            value => Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Unexpected value for angle units: `{value}`; expected one of `deg`, `rad`"),
+                vec![source_range],
+            ))),
         }
     }
 }

rust/kcl-lib/src/execution/artifact.rs

@@ -941,12 +941,10 @@ fn artifacts_to_update(
         ModelingCmd::StartPath(_) => {
             let mut return_arr = Vec::new();
             let current_plane_id = path_to_plane_id_map.get(&artifact_command.cmd_id).ok_or_else(|| {
-                KclError::Internal(KclErrorDetails {
-                    message: format!(
-                        "Expected a current plane ID when processing StartPath command, but we have none: {id:?}"
-                    ),
-                    source_ranges: vec![range],
-                })
+                KclError::Internal(KclErrorDetails::new(
+                    format!("Expected a current plane ID when processing StartPath command, but we have none: {id:?}"),
+                    vec![range],
+                ))
             })?;
             return_arr.push(Artifact::Path(Path {
                 id,
@@ -1065,10 +1063,10 @@ fn artifacts_to_update(
                 // TODO: Using the first one.  Make sure to revisit this
                 // choice, don't think it matters for now.
                 path_id: ArtifactId::new(*loft_cmd.section_ids.first().ok_or_else(|| {
-                    KclError::Internal(KclErrorDetails {
-                        message: format!("Expected at least one section ID in Loft command: {id:?}; cmd={cmd:?}"),
-                        source_ranges: vec![range],
-                    })
+                    KclError::Internal(KclErrorDetails::new(
+                        format!("Expected at least one section ID in Loft command: {id:?}; cmd={cmd:?}"),
+                        vec![range],
+                    ))
                 })?),
                 surface_ids: Vec::new(),
                 edge_ids: Vec::new(),
@@ -1108,12 +1106,12 @@ fn artifacts_to_update(
                 };
                 last_path = Some(path);
                 let path_sweep_id = path.sweep_id.ok_or_else(|| {
-                    KclError::Internal(KclErrorDetails {
-                        message:format!(
+                    KclError::Internal(KclErrorDetails::new(
+                        format!(
                             "Expected a sweep ID on the path when processing Solid3dGetExtrusionFaceInfo command, but we have none: {id:?}, {path:?}"
                         ),
-                        source_ranges: vec![range],
-                    })
+                        vec![range],
+                    ))
                 })?;
                 let extra_artifact = exec_artifacts.values().find(|a| {
                     if let Artifact::StartSketchOnFace(s) = a {
@@ -1162,12 +1160,12 @@ fn artifacts_to_update(
                         continue;
                     };
                     let path_sweep_id = path.sweep_id.ok_or_else(|| {
-                        KclError::Internal(KclErrorDetails {
-                            message:format!(
+                        KclError::Internal(KclErrorDetails::new(
+                            format!(
                                 "Expected a sweep ID on the path when processing last path's Solid3dGetExtrusionFaceInfo command, but we have none: {id:?}, {path:?}"
                             ),
-                            source_ranges: vec![range],
-                        })
+                            vec![range],
+                        ))
                     })?;
                     let extra_artifact = exec_artifacts.values().find(|a| {
                         if let Artifact::StartSketchOnFace(s) = a {

rust/kcl-lib/src/execution/exec_ast.rs

@@ -131,10 +131,10 @@ impl ExecutorContext {
             match statement {
                 BodyItem::ImportStatement(import_stmt) => {
                     if !matches!(body_type, BodyType::Root) {
-                        return Err(KclError::Semantic(KclErrorDetails {
-                            message: "Imports are only supported at the top-level of a file.".to_owned(),
-                            source_ranges: vec![import_stmt.into()],
-                        }));
+                        return Err(KclError::Semantic(KclErrorDetails::new(
+                            "Imports are only supported at the top-level of a file.".to_owned(),
+                            vec![import_stmt.into()],
+                        )));
                     }
 
                     let source_range = SourceRange::from(import_stmt);
@@ -157,28 +157,25 @@ impl ExecutorContext {
                                 let mut ty = mem.get_from(&ty_name, env_ref, import_item.into(), 0).cloned();
 
                                 if value.is_err() && ty.is_err() {
-                                    return Err(KclError::UndefinedValue(KclErrorDetails {
-                                        message: format!("{} is not defined in module", import_item.name.name),
-                                        source_ranges: vec![SourceRange::from(&import_item.name)],
-                                    }));
+                                    return Err(KclError::UndefinedValue(KclErrorDetails::new(
+                                        format!("{} is not defined in module", import_item.name.name),
+                                        vec![SourceRange::from(&import_item.name)],
+                                    )));
                                 }
 
                                 // Check that the item is allowed to be imported (in at least one namespace).
                                 if value.is_ok() && !module_exports.contains(&import_item.name.name) {
-                                    value = Err(KclError::Semantic(KclErrorDetails {
-                                        message: format!(
+                                    value = Err(KclError::Semantic(KclErrorDetails::new(
+                                        format!(
                                             "Cannot import \"{}\" from module because it is not exported. Add \"export\" before the definition to export it.",
                                             import_item.name.name
                                         ),
-                                        source_ranges: vec![SourceRange::from(&import_item.name)],
-                                    }));
+                                        vec![SourceRange::from(&import_item.name)],
+                                    )));
                                 }
 
                                 if ty.is_ok() && !module_exports.contains(&ty_name) {
-                                    ty = Err(KclError::Semantic(KclErrorDetails {
-                                        message: String::new(),
-                                        source_ranges: vec![],
-                                    }));
+                                    ty = Err(KclError::Semantic(KclErrorDetails::new(String::new(), vec![])));
                                 }
 
                                 if value.is_err() && ty.is_err() {
@@ -225,10 +222,10 @@ impl ExecutorContext {
                                     .memory
                                     .get_from(name, env_ref, source_range, 0)
                                     .map_err(|_err| {
-                                        KclError::Internal(KclErrorDetails {
-                                            message: format!("{} is not defined in module (but was exported?)", name),
-                                            source_ranges: vec![source_range],
-                                        })
+                                        KclError::Internal(KclErrorDetails::new(
+                                            format!("{} is not defined in module (but was exported?)", name),
+                                            vec![source_range],
+                                        ))
                                     })?
                                     .clone();
                                 exec_state.mut_stack().add(name.to_owned(), item, source_range)?;
@@ -297,10 +294,10 @@ impl ExecutorContext {
                             let std_path = match &exec_state.mod_local.std_path {
                                 Some(p) => p,
                                 None => {
-                                    return Err(KclError::Semantic(KclErrorDetails {
-                                        message: "User-defined types are not yet supported.".to_owned(),
-                                        source_ranges: vec![metadata.source_range],
-                                    }));
+                                    return Err(KclError::Semantic(KclErrorDetails::new(
+                                        "User-defined types are not yet supported.".to_owned(),
+                                        vec![metadata.source_range],
+                                    )));
                                 }
                             };
                             let (t, props) = crate::std::std_ty(std_path, &ty.name.name);
@@ -313,10 +310,10 @@ impl ExecutorContext {
                                 .mut_stack()
                                 .add(name_in_mem.clone(), value, metadata.source_range)
                                 .map_err(|_| {
-                                    KclError::Semantic(KclErrorDetails {
-                                        message: format!("Redefinition of type {}.", ty.name.name),
-                                        source_ranges: vec![metadata.source_range],
-                                    })
+                                    KclError::Semantic(KclErrorDetails::new(
+                                        format!("Redefinition of type {}.", ty.name.name),
+                                        vec![metadata.source_range],
+                                    ))
                                 })?;
 
                             if let ItemVisibility::Export = ty.visibility {
@@ -343,10 +340,10 @@ impl ExecutorContext {
                                     .mut_stack()
                                     .add(name_in_mem.clone(), value, metadata.source_range)
                                     .map_err(|_| {
-                                        KclError::Semantic(KclErrorDetails {
-                                            message: format!("Redefinition of type {}.", ty.name.name),
-                                            source_ranges: vec![metadata.source_range],
-                                        })
+                                        KclError::Semantic(KclErrorDetails::new(
+                                            format!("Redefinition of type {}.", ty.name.name),
+                                            vec![metadata.source_range],
+                                        ))
                                     })?;
 
                                 if let ItemVisibility::Export = ty.visibility {
@@ -354,10 +351,10 @@ impl ExecutorContext {
                                 }
                             }
                             None => {
-                                return Err(KclError::Semantic(KclErrorDetails {
-                                    message: "User-defined types are not yet supported.".to_owned(),
-                                    source_ranges: vec![metadata.source_range],
-                                }))
+                                return Err(KclError::Semantic(KclErrorDetails::new(
+                                    "User-defined types are not yet supported.".to_owned(),
+                                    vec![metadata.source_range],
+                                )))
                             }
                         },
                     }
@@ -368,10 +365,10 @@ impl ExecutorContext {
                     let metadata = Metadata::from(return_statement);
 
                     if matches!(body_type, BodyType::Root) {
-                        return Err(KclError::Semantic(KclErrorDetails {
-                            message: "Cannot return from outside a function.".to_owned(),
-                            source_ranges: vec![metadata.source_range],
-                        }));
+                        return Err(KclError::Semantic(KclErrorDetails::new(
+                            "Cannot return from outside a function.".to_owned(),
+                            vec![metadata.source_range],
+                        )));
                     }
 
                     let value = self
@@ -387,10 +384,10 @@ impl ExecutorContext {
                         .mut_stack()
                         .add(memory::RETURN_NAME.to_owned(), value, metadata.source_range)
                         .map_err(|_| {
-                            KclError::Semantic(KclErrorDetails {
-                                message: "Multiple returns from a single function.".to_owned(),
-                                source_ranges: vec![metadata.source_range],
-                            })
+                            KclError::Semantic(KclErrorDetails::new(
+                                "Multiple returns from a single function.".to_owned(),
+                                vec![metadata.source_range],
+                            ))
                         })?;
                     last_expr = None;
                 }
@@ -493,10 +490,10 @@ impl ExecutorContext {
                     *cache = Some((val, er, items.clone()));
                     (er, items)
                 }),
-            ModuleRepr::Foreign(geom, _) => Err(KclError::Semantic(KclErrorDetails {
-                message: "Cannot import items from foreign modules".to_owned(),
-                source_ranges: vec![geom.source_range],
-            })),
+            ModuleRepr::Foreign(geom, _) => Err(KclError::Semantic(KclErrorDetails::new(
+                "Cannot import items from foreign modules".to_owned(),
+                vec![geom.source_range],
+            ))),
             ModuleRepr::Dummy => unreachable!("Looking up {}, but it is still being interpreted", path),
         };
 
@@ -572,13 +569,13 @@ impl ExecutorContext {
                 err.override_source_ranges(vec![source_range])
             } else {
                 // TODO would be great to have line/column for the underlying error here
-                KclError::Semantic(KclErrorDetails {
-                    message: format!(
+                KclError::Semantic(KclErrorDetails::new(
+                    format!(
                         "Error loading imported file ({path}). Open it to view more details.\n  {}",
                         err.message()
                     ),
-                    source_ranges: vec![source_range],
-                })
+                    vec![source_range],
+                ))
             }
         })
     }
@@ -639,11 +636,10 @@ impl ExecutorContext {
                             meta: vec![metadata.to_owned()],
                         }
                     } else {
-                        return Err(KclError::Semantic(KclErrorDetails {
-                            message: "Rust implementation of functions is restricted to the standard library"
-                                .to_owned(),
-                            source_ranges: vec![metadata.source_range],
-                        }));
+                        return Err(KclError::Semantic(KclErrorDetails::new(
+                            "Rust implementation of functions is restricted to the standard library".to_owned(),
+                            vec![metadata.source_range],
+                        )));
                     }
                 } else {
                     // Snapshotting memory here is crucial for semantics so that we close
@@ -667,18 +663,18 @@ impl ExecutorContext {
                         "you cannot declare variable {name} as %, because % can only be used in function calls"
                     );
 
-                    return Err(KclError::Semantic(KclErrorDetails {
+                    return Err(KclError::Semantic(KclErrorDetails::new(
                         message,
-                        source_ranges: vec![pipe_substitution.into()],
-                    }));
+                        vec![pipe_substitution.into()],
+                    )));
                 }
                 StatementKind::Expression => match exec_state.mod_local.pipe_value.clone() {
                     Some(x) => x,
                     None => {
-                        return Err(KclError::Semantic(KclErrorDetails {
-                            message: "cannot use % outside a pipe expression".to_owned(),
-                            source_ranges: vec![pipe_substitution.into()],
-                        }));
+                        return Err(KclError::Semantic(KclErrorDetails::new(
+                            "cannot use % outside a pipe expression".to_owned(),
+                            vec![pipe_substitution.into()],
+                        )));
                     }
                 },
             },
@@ -750,13 +746,13 @@ fn apply_ascription(
         } else {
             ""
         };
-        KclError::Semantic(KclErrorDetails {
-            message: format!(
+        KclError::Semantic(KclErrorDetails::new(
+            format!(
                 "could not coerce {} value to type {ty}{suggestion}",
                 value.human_friendly_type()
             ),
-            source_ranges: vec![source_range],
-        })
+            vec![source_range],
+        ))
     })
 }
 
@@ -783,10 +779,10 @@ impl Node<Name> {
         ctx: &ExecutorContext,
     ) -> Result<&'a KclValue, KclError> {
         if self.abs_path {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "Absolute paths (names beginning with `::` are not yet supported)".to_owned(),
-                source_ranges: self.as_source_ranges(),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "Absolute paths (names beginning with `::` are not yet supported)".to_owned(),
+                self.as_source_ranges(),
+            )));
         }
 
         if self.path.is_empty() {
@@ -798,10 +794,10 @@ impl Node<Name> {
             let value = match mem_spec {
                 Some((env, exports)) => {
                     if !exports.contains(&p.name) {
-                        return Err(KclError::Semantic(KclErrorDetails {
-                            message: format!("Item {} not found in module's exported items", p.name),
-                            source_ranges: p.as_source_ranges(),
-                        }));
+                        return Err(KclError::Semantic(KclErrorDetails::new(
+                            format!("Item {} not found in module's exported items", p.name),
+                            p.as_source_ranges(),
+                        )));
                     }
 
                     exec_state
@@ -813,13 +809,13 @@ impl Node<Name> {
             };
 
             let KclValue::Module { value: module_id, .. } = value else {
-                return Err(KclError::Semantic(KclErrorDetails {
-                    message: format!(
+                return Err(KclError::Semantic(KclErrorDetails::new(
+                    format!(
                         "Identifier in path must refer to a module, found {}",
                         value.human_friendly_type()
                     ),
-                    source_ranges: p.as_source_ranges(),
-                }));
+                    p.as_source_ranges(),
+                )));
             };
 
             mem_spec = Some(
@@ -830,10 +826,10 @@ impl Node<Name> {
 
         let (env, exports) = mem_spec.unwrap();
         if !exports.contains(&self.name.name) {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Item {} not found in module's exported items", self.name.name),
-                source_ranges: self.name.as_source_ranges(),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Item {} not found in module's exported items", self.name.name),
+                self.name.as_source_ranges(),
+            )));
         }
 
         exec_state
@@ -861,46 +857,44 @@ impl Node<MemberExpression> {
                 if let Some(value) = map.get(&property) {
                     Ok(value.to_owned())
                 } else {
-                    Err(KclError::UndefinedValue(KclErrorDetails {
-                        message: format!("Property '{property}' not found in object"),
-                        source_ranges: vec![self.clone().into()],
-                    }))
+                    Err(KclError::UndefinedValue(KclErrorDetails::new(
+                        format!("Property '{property}' not found in object"),
+                        vec![self.clone().into()],
+                    )))
                 }
             }
-            (KclValue::Object { .. }, Property::String(property), true) => Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Cannot index object with string; use dot notation instead, e.g. `obj.{property}`"),
-                source_ranges: vec![self.clone().into()],
-            })),
+            (KclValue::Object { .. }, Property::String(property), true) => {
+                Err(KclError::Semantic(KclErrorDetails::new(
+                    format!("Cannot index object with string; use dot notation instead, e.g. `obj.{property}`"),
+                    vec![self.clone().into()],
+                )))
+            }
             (KclValue::Object { .. }, p, _) => {
                 let t = p.type_name();
                 let article = article_for(t);
-                Err(KclError::Semantic(KclErrorDetails {
-                    message: format!(
-                        "Only strings can be used as the property of an object, but you're using {article} {t}",
-                    ),
-                    source_ranges: vec![self.clone().into()],
-                }))
+                Err(KclError::Semantic(KclErrorDetails::new(
+                    format!("Only strings can be used as the property of an object, but you're using {article} {t}",),
+                    vec![self.clone().into()],
+                )))
             }
             (KclValue::HomArray { value: arr, .. }, Property::UInt(index), _) => {
                 let value_of_arr = arr.get(index);
                 if let Some(value) = value_of_arr {
                     Ok(value.to_owned())
                 } else {
-                    Err(KclError::UndefinedValue(KclErrorDetails {
-                        message: format!("The array doesn't have any item at index {index}"),
-                        source_ranges: vec![self.clone().into()],
-                    }))
+                    Err(KclError::UndefinedValue(KclErrorDetails::new(
+                        format!("The array doesn't have any item at index {index}"),
+                        vec![self.clone().into()],
+                    )))
                 }
             }
             (KclValue::HomArray { .. }, p, _) => {
                 let t = p.type_name();
                 let article = article_for(t);
-                Err(KclError::Semantic(KclErrorDetails {
-                    message: format!(
-                        "Only integers >= 0 can be used as the index of an array, but you're using {article} {t}",
-                    ),
-                    source_ranges: vec![self.clone().into()],
-                }))
+                Err(KclError::Semantic(KclErrorDetails::new(
+                    format!("Only integers >= 0 can be used as the index of an array, but you're using {article} {t}",),
+                    vec![self.clone().into()],
+                )))
             }
             (KclValue::Solid { value }, Property::String(prop), false) if prop == "sketch" => Ok(KclValue::Sketch {
                 value: Box::new(value.sketch),
@@ -918,10 +912,10 @@ impl Node<MemberExpression> {
             (being_indexed, _, _) => {
                 let t = being_indexed.human_friendly_type();
                 let article = article_for(&t);
-                Err(KclError::Semantic(KclErrorDetails {
-                    message: format!("Only arrays can be indexed, but you're trying to index {article} {t}"),
-                    source_ranges: vec![self.clone().into()],
-                }))
+                Err(KclError::Semantic(KclErrorDetails::new(
+                    format!("Only arrays can be indexed, but you're trying to index {article} {t}"),
+                    vec![self.clone().into()],
+                )))
             }
         }
     }
@@ -996,26 +990,26 @@ impl Node<BinaryExpression> {
                 meta: _,
             } = left_value
             else {
-                return Err(KclError::Semantic(KclErrorDetails {
-                    message: format!(
+                return Err(KclError::Semantic(KclErrorDetails::new(
+                    format!(
                         "Cannot apply logical operator to non-boolean value: {}",
                         left_value.human_friendly_type()
                     ),
-                    source_ranges: vec![self.left.clone().into()],
-                }));
+                    vec![self.left.clone().into()],
+                )));
             };
             let KclValue::Bool {
                 value: right_value,
                 meta: _,
             } = right_value
             else {
-                return Err(KclError::Semantic(KclErrorDetails {
-                    message: format!(
+                return Err(KclError::Semantic(KclErrorDetails::new(
+                    format!(
                         "Cannot apply logical operator to non-boolean value: {}",
                         right_value.human_friendly_type()
                     ),
-                    source_ranges: vec![self.right.clone().into()],
-                }));
+                    vec![self.right.clone().into()],
+                )));
             };
             let raw_value = match self.operator {
                 BinaryOperator::Or => left_value || right_value,
@@ -1115,13 +1109,13 @@ impl Node<UnaryExpression> {
                 meta: _,
             } = value
             else {
-                return Err(KclError::Semantic(KclErrorDetails {
-                    message: format!(
+                return Err(KclError::Semantic(KclErrorDetails::new(
+                    format!(
                         "Cannot apply unary operator ! to non-boolean value: {}",
                         value.human_friendly_type()
                     ),
-                    source_ranges: vec![self.into()],
-                }));
+                    vec![self.into()],
+                )));
             };
             let meta = vec![Metadata {
                 source_range: self.into(),
@@ -1136,13 +1130,13 @@ impl Node<UnaryExpression> {
 
         let value = &self.argument.get_result(exec_state, ctx).await?;
         let err = || {
-            KclError::Semantic(KclErrorDetails {
-                message: format!(
+            KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "You can only negate numbers, planes, or lines, but this is a {}",
                     value.human_friendly_type()
                 ),
-                source_ranges: vec![self.into()],
-            })
+                vec![self.into()],
+            ))
         };
         match value {
             KclValue::Number { value, ty, .. } => {
@@ -1239,10 +1233,10 @@ pub(crate) async fn execute_pipe_body(
     ctx: &ExecutorContext,
 ) -> Result<KclValue, KclError> {
     let Some((first, body)) = body.split_first() else {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message: "Pipe expressions cannot be empty".to_owned(),
-            source_ranges: vec![source_range],
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            "Pipe expressions cannot be empty".to_owned(),
+            vec![source_range],
+        )));
     };
     // Evaluate the first element in the pipeline.
     // They use the pipe_value from some AST node above this, so that if pipe expression is nested in a larger pipe expression,
@@ -1277,10 +1271,10 @@ async fn inner_execute_pipe_body(
 ) -> Result<KclValue, KclError> {
     for expression in body {
         if let Expr::TagDeclarator(_) = expression {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!("This cannot be in a PipeExpression: {:?}", expression),
-                source_ranges: vec![expression.into()],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("This cannot be in a PipeExpression: {:?}", expression),
+                vec![expression.into()],
+            )));
         }
         let metadata = Metadata {
             source_range: SourceRange::from(expression),
@@ -1349,35 +1343,37 @@ impl Node<ArrayRangeExpression> {
                 StatementKind::Expression,
             )
             .await?;
-        let (start, start_ty) = start_val.as_int_with_ty().ok_or(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![self.into()],
-            message: format!("Expected int but found {}", start_val.human_friendly_type()),
-        }))?;
+        let (start, start_ty) = start_val
+            .as_int_with_ty()
+            .ok_or(KclError::Semantic(KclErrorDetails::new(
+                format!("Expected int but found {}", start_val.human_friendly_type()),
+                vec![self.into()],
+            )))?;
         let metadata = Metadata::from(&self.end_element);
         let end_val = ctx
             .execute_expr(&self.end_element, exec_state, &metadata, &[], StatementKind::Expression)
             .await?;
-        let (end, end_ty) = end_val.as_int_with_ty().ok_or(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![self.into()],
-            message: format!("Expected int but found {}", end_val.human_friendly_type()),
-        }))?;
+        let (end, end_ty) = end_val.as_int_with_ty().ok_or(KclError::Semantic(KclErrorDetails::new(
+            format!("Expected int but found {}", end_val.human_friendly_type()),
+            vec![self.into()],
+        )))?;
 
         if start_ty != end_ty {
             let start = start_val.as_ty_f64().unwrap_or(TyF64 { n: 0.0, ty: start_ty });
             let start = fmt::human_display_number(start.n, start.ty);
             let end = end_val.as_ty_f64().unwrap_or(TyF64 { n: 0.0, ty: end_ty });
             let end = fmt::human_display_number(end.n, end.ty);
-            return Err(KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![self.into()],
-                message: format!("Range start and end must be of the same type, but found {start} and {end}"),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Range start and end must be of the same type, but found {start} and {end}"),
+                vec![self.into()],
+            )));
         }
 
         if end < start {
-            return Err(KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![self.into()],
-                message: format!("Range start is greater than range end: {start} .. {end}"),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Range start is greater than range end: {start} .. {end}"),
+                vec![self.into()],
+            )));
         }
 
         let range: Vec<_> = if self.end_inclusive {
@@ -1438,10 +1434,10 @@ fn article_for<S: AsRef<str>>(s: S) -> &'static str {
 fn number_as_f64(v: &KclValue, source_range: SourceRange) -> Result<TyF64, KclError> {
     v.as_ty_f64().ok_or_else(|| {
         let actual_type = v.human_friendly_type();
-        KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![source_range],
-            message: format!("Expected a number, but found {actual_type}",),
-        })
+        KclError::Semantic(KclErrorDetails::new(
+            format!("Expected a number, but found {actual_type}",),
+            vec![source_range],
+        ))
     })
 }
 
@@ -1530,16 +1526,16 @@ impl Property {
                         if let Some(x) = crate::try_f64_to_usize(value) {
                             Ok(Property::UInt(x))
                         } else {
-                            Err(KclError::Semantic(KclErrorDetails {
-                                source_ranges: property_sr,
-                                message: format!("{value} is not a valid index, indices must be whole numbers >= 0"),
-                            }))
+                            Err(KclError::Semantic(KclErrorDetails::new(
+                                format!("{value} is not a valid index, indices must be whole numbers >= 0"),
+                                property_sr,
+                            )))
                         }
                     }
-                    _ => Err(KclError::Semantic(KclErrorDetails {
-                        source_ranges: vec![sr],
-                        message: "Only numbers (>= 0) can be indexes".to_owned(),
-                    })),
+                    _ => Err(KclError::Semantic(KclErrorDetails::new(
+                        "Only numbers (>= 0) can be indexes".to_owned(),
+                        vec![sr],
+                    ))),
                 }
             }
         }
@@ -1547,12 +1543,7 @@ impl Property {
 }
 
 fn jvalue_to_prop(value: &KclValue, property_sr: Vec<SourceRange>, name: &str) -> Result<Property, KclError> {
-    let make_err = |message: String| {
-        Err::<Property, _>(KclError::Semantic(KclErrorDetails {
-            source_ranges: property_sr,
-            message,
-        }))
-    };
+    let make_err = |message: String| Err::<Property, _>(KclError::Semantic(KclErrorDetails::new(message, property_sr)));
     match value {
         KclValue::Number{value: num, .. } => {
             let num = *num;
@@ -1795,10 +1786,10 @@ d = b + c
                 crate::engine::conn_mock::EngineConnection::new()
                     .await
                     .map_err(|err| {
-                        KclError::Internal(crate::errors::KclErrorDetails {
-                            message: format!("Failed to create mock engine connection: {}", err),
-                            source_ranges: vec![SourceRange::default()],
-                        })
+                        KclError::Internal(KclErrorDetails::new(
+                            format!("Failed to create mock engine connection: {}", err),
+                            vec![SourceRange::default()],
+                        ))
                     })
                     .unwrap(),
             )),

rust/kcl-lib/src/execution/fn_call.rs

@@ -1,13 +1,16 @@
 use async_recursion::async_recursion;
 use indexmap::IndexMap;
 
-use crate::execution::cad_op::{Group, OpArg, OpKclValue, Operation};
+use super::{types::ArrayLen, EnvironmentRef};
 use crate::{
     docs::StdLibFn,
     errors::{KclError, KclErrorDetails},
     execution::{
-        kcl_value::FunctionSource, memory, types::RuntimeType, BodyType, ExecState, ExecutorContext, KclValue,
-        Metadata, StatementKind, TagEngineInfo, TagIdentifier,
+        cad_op::{Group, OpArg, OpKclValue, Operation},
+        kcl_value::FunctionSource,
+        memory,
+        types::RuntimeType,
+        BodyType, ExecState, ExecutorContext, KclValue, Metadata, StatementKind, TagEngineInfo, TagIdentifier,
     },
     parsing::ast::types::{CallExpressionKw, DefaultParamVal, FunctionExpression, Node, Program, Type},
     source_range::SourceRange,
@@ -15,9 +18,6 @@ use crate::{
     CompilationError,
 };
 
-use super::types::ArrayLen;
-use super::EnvironmentRef;
-
 #[derive(Debug, Clone)]
 pub struct Args {
     /// Positional args.
@@ -281,6 +281,13 @@ impl Node<CallExpressionKw> {
                 def.call_kw(Some(func.name()), exec_state, ctx, args, callsite)
                     .await
                     .map(Option::unwrap)
+                    .map_err(|e| {
+                        // This is used for the backtrace display.  We don't add
+                        // another location the way we do for user-defined
+                        // functions because the error uses the Args, which
+                        // already points here.
+                        e.set_last_backtrace_fn_name(Some(func.name()))
+                    })
             }
             None => {
                 // Clone the function so that we can use a mutable reference to
@@ -288,10 +295,10 @@ impl Node<CallExpressionKw> {
                 let func = fn_name.get_result(exec_state, ctx).await?.clone();
 
                 let Some(fn_src) = func.as_fn() else {
-                    return Err(KclError::Semantic(KclErrorDetails {
-                        message: "cannot call this because it isn't a function".to_string(),
-                        source_ranges: vec![callsite],
-                    }));
+                    return Err(KclError::Semantic(KclErrorDetails::new(
+                        "cannot call this because it isn't a function".to_string(),
+                        vec![callsite],
+                    )));
                 };
 
                 let return_value = fn_src
@@ -299,7 +306,10 @@ impl Node<CallExpressionKw> {
                     .await
                     .map_err(|e| {
                         // Add the call expression to the source ranges.
-                        e.add_source_ranges(vec![callsite])
+                        //
+                        // TODO: Use the name that the function was defined
+                        // with, not the identifier it was used with.
+                        e.add_unwind_location(Some(fn_name.name.name.clone()), callsite)
                     })?;
 
                 let result = return_value.ok_or_else(move || {
@@ -308,10 +318,10 @@ impl Node<CallExpressionKw> {
                     if let KclValue::Function { meta, .. } = func {
                         source_ranges = meta.iter().map(|m| m.source_range).collect();
                     };
-                    KclError::UndefinedValue(KclErrorDetails {
-                        message: format!("Result of user-defined function {} is undefined", fn_name),
+                    KclError::UndefinedValue(KclErrorDetails::new(
+                        format!("Result of user-defined function {} is undefined", fn_name),
                         source_ranges,
-                    })
+                    ))
                 })?;
 
                 Ok(result)
@@ -490,10 +500,10 @@ fn update_memory_for_tags_of_geometry(result: &mut KclValue, exec_state: &mut Ex
                     let tag_id = if let Some(t) = value.sketch.tags.get(&tag.name) {
                         let mut t = t.clone();
                         let Some(info) = t.get_cur_info() else {
-                            return Err(KclError::Internal(KclErrorDetails {
-                                message: format!("Tag {} does not have path info", tag.name),
-                                source_ranges: vec![tag.into()],
-                            }));
+                            return Err(KclError::Internal(KclErrorDetails::new(
+                                format!("Tag {} does not have path info", tag.name),
+                                vec![tag.into()],
+                            )));
                         };
 
                         let mut info = info.clone();
@@ -608,10 +618,10 @@ fn type_check_params_kw(
                                 // TODO if we have access to the AST for the argument we could choose which example to suggest.
                                 message = format!("{message}\n\nYou may need to add information about the type of the argument, for example:\n  using a numeric suffix: `42{ty}`\n  or using type ascription: `foo(): number({ty})`");
                             }
-                            KclError::Semantic(KclErrorDetails {
+                            KclError::Semantic(KclErrorDetails::new(
                                 message,
-                                source_ranges: vec![arg.source_range],
-                            })
+                                vec![arg.source_range],
+                            ))
                         })?;
                 }
             }
@@ -673,8 +683,8 @@ fn type_check_params_kw(
                     exec_state,
                 )
                 .map_err(|_| {
-                    KclError::Semantic(KclErrorDetails {
-                        message: format!(
+                    KclError::Semantic(KclErrorDetails::new(
+                        format!(
                             "The input argument of {} requires a value with type `{}`, but found {}",
                             fn_name
                                 .map(|n| format!("`{}`", n))
@@ -682,8 +692,8 @@ fn type_check_params_kw(
                             ty,
                             arg.1.value.human_friendly_type()
                         ),
-                        source_ranges: vec![arg.1.source_range],
-                    })
+                        vec![arg.1.source_range],
+                    ))
                 })?;
         }
     } else if let Some((name, _)) = &fn_def.input_arg {
@@ -730,13 +740,13 @@ fn assign_args_to_params_kw(
                         .add(name.clone(), value, default_val.source_range())?;
                 }
                 None => {
-                    return Err(KclError::Semantic(KclErrorDetails {
-                        source_ranges,
-                        message: format!(
+                    return Err(KclError::Semantic(KclErrorDetails::new(
+                        format!(
                             "This function requires a parameter {}, but you haven't passed it one.",
                             name
                         ),
-                    }));
+                        source_ranges,
+                    )));
                 }
             },
         }
@@ -747,16 +757,15 @@ fn assign_args_to_params_kw(
 
         let Some(unlabeled) = unlabelled else {
             return Err(if args.kw_args.labeled.contains_key(param_name) {
-                KclError::Semantic(KclErrorDetails {
+                KclError::Semantic(KclErrorDetails::new(
+                    format!("The function does declare a parameter named '{param_name}', but this parameter doesn't use a label. Try removing the `{param_name}:`"),
                     source_ranges,
-                    message: format!("The function does declare a parameter named '{param_name}', but this parameter doesn't use a label. Try removing the `{param_name}:`"),
-                })
+                ))
             } else {
-                KclError::Semantic(KclErrorDetails {
+                KclError::Semantic(KclErrorDetails::new(
+                    "This function expects an unlabeled first parameter, but you haven't passed it one.".to_owned(),
                     source_ranges,
-                    message: "This function expects an unlabeled first parameter, but you haven't passed it one."
-                        .to_owned(),
-                })
+                ))
             });
         };
         exec_state.mut_stack().add(
@@ -789,14 +798,14 @@ fn coerce_result_type(
                 ty = RuntimeType::Union(vec![(**inner).clone(), ty]);
             }
             let val = val.coerce(&ty, exec_state).map_err(|_| {
-                KclError::Semantic(KclErrorDetails {
-                    message: format!(
+                KclError::Semantic(KclErrorDetails::new(
+                    format!(
                         "This function requires its result to be of type `{}`, but found {}",
                         ty.human_friendly_type(),
                         val.human_friendly_type(),
                     ),
-                    source_ranges: ret_ty.as_source_ranges(),
-                })
+                    ret_ty.as_source_ranges(),
+                ))
             })?;
             Ok(Some(val))
         } else {
@@ -873,10 +882,10 @@ mod test {
                 "all params required, none given, should error",
                 vec![req_param("x")],
                 vec![],
-                Err(KclError::Semantic(KclErrorDetails {
-                    source_ranges: vec![SourceRange::default()],
-                    message: "This function requires a parameter x, but you haven't passed it one.".to_owned(),
-                })),
+                Err(KclError::Semantic(KclErrorDetails::new(
+                    "This function requires a parameter x, but you haven't passed it one.".to_owned(),
+                    vec![SourceRange::default()],
+                ))),
             ),
             (
                 "all params optional, none given, should be OK",
@@ -888,10 +897,10 @@ mod test {
                 "mixed params, too few given",
                 vec![req_param("x"), opt_param("y")],
                 vec![],
-                Err(KclError::Semantic(KclErrorDetails {
-                    source_ranges: vec![SourceRange::default()],
-                    message: "This function requires a parameter x, but you haven't passed it one.".to_owned(),
-                })),
+                Err(KclError::Semantic(KclErrorDetails::new(
+                    "This function requires a parameter x, but you haven't passed it one.".to_owned(),
+                    vec![SourceRange::default()],
+                ))),
             ),
             (
                 "mixed params, minimum given, should be OK",

rust/kcl-lib/src/execution/geometry.rs

@@ -469,18 +469,18 @@ impl TryFrom<PlaneData> for PlaneInfo {
             PlaneData::NegYZ => PlaneName::NegYz,
             PlaneData::Plane(_) => {
                 // We will never get here since we already checked for PlaneData::Plane.
-                return Err(KclError::Internal(KclErrorDetails {
-                    message: format!("PlaneData {:?} not found", value),
-                    source_ranges: Default::default(),
-                }));
+                return Err(KclError::Internal(KclErrorDetails::new(
+                    format!("PlaneData {:?} not found", value),
+                    Default::default(),
+                )));
             }
         };
 
         let info = DEFAULT_PLANE_INFO.get(&name).ok_or_else(|| {
-            KclError::Internal(KclErrorDetails {
-                message: format!("Plane {} not found", name),
-                source_ranges: Default::default(),
-            })
+            KclError::Internal(KclErrorDetails::new(
+                format!("Plane {} not found", name),
+                Default::default(),
+            ))
         })?;
 
         Ok(info.clone())

rust/kcl-lib/src/execution/import.rs

@@ -37,53 +37,43 @@ pub async fn import_foreign(
 ) -> Result<PreImportedGeometry, KclError> {
     // Make sure the file exists.
     if !ctxt.fs.exists(file_path, source_range).await? {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message: format!("File `{}` does not exist.", file_path.display()),
-            source_ranges: vec![source_range],
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            format!("File `{}` does not exist.", file_path.display()),
+            vec![source_range],
+        )));
     }
 
     let ext_format = get_import_format_from_extension(file_path.extension().ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
-            message: format!("No file extension found for `{}`", file_path.display()),
-            source_ranges: vec![source_range],
-        })
+        KclError::Semantic(KclErrorDetails::new(
+            format!("No file extension found for `{}`", file_path.display()),
+            vec![source_range],
+        ))
     })?)
-    .map_err(|e| {
-        KclError::Semantic(KclErrorDetails {
-            message: e.to_string(),
-            source_ranges: vec![source_range],
-        })
-    })?;
+    .map_err(|e| KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;
 
     // Get the format type from the extension of the file.
     let format = if let Some(format) = format {
         // Validate the given format with the extension format.
-        validate_extension_format(ext_format, format.clone()).map_err(|e| {
-            KclError::Semantic(KclErrorDetails {
-                message: e.to_string(),
-                source_ranges: vec![source_range],
-            })
-        })?;
+        validate_extension_format(ext_format, format.clone())
+            .map_err(|e| KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;
         format
     } else {
         ext_format
     };
 
     // Get the file contents for each file path.
-    let file_contents = ctxt.fs.read(file_path, source_range).await.map_err(|e| {
-        KclError::Semantic(KclErrorDetails {
-            message: e.to_string(),
-            source_ranges: vec![source_range],
-        })
-    })?;
+    let file_contents = ctxt
+        .fs
+        .read(file_path, source_range)
+        .await
+        .map_err(|e| KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;
 
     // We want the file_path to be without the parent.
     let file_name = file_path.file_name().map(|p| p.to_string()).ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
-            message: format!("Could not get the file name from the path `{}`", file_path.display()),
-            source_ranges: vec![source_range],
-        })
+        KclError::Semantic(KclErrorDetails::new(
+            format!("Could not get the file name from the path `{}`", file_path.display()),
+            vec![source_range],
+        ))
     })?;
     let mut import_files = vec![kcmc::ImportFile {
         path: file_name.to_string(),
@@ -96,12 +86,8 @@ pub async fn import_foreign(
         // Check if the file is a binary gltf file, in that case we don't need to import the bin
         // file.
         if !file_contents.starts_with(b"glTF") {
-            let json = gltf_json::Root::from_slice(&file_contents).map_err(|e| {
-                KclError::Semantic(KclErrorDetails {
-                    message: e.to_string(),
-                    source_ranges: vec![source_range],
-                })
-            })?;
+            let json = gltf_json::Root::from_slice(&file_contents)
+                .map_err(|e| KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;
 
             // Read the gltf file and check if there is a bin file.
             for buffer in json.buffers.iter() {
@@ -109,17 +95,15 @@ pub async fn import_foreign(
                     if !uri.starts_with("data:") {
                         // We want this path relative to the file_path given.
                         let bin_path = file_path.parent().map(|p| p.join(uri)).ok_or_else(|| {
-                            KclError::Semantic(KclErrorDetails {
-                                message: format!("Could not get the parent path of the file `{}`", file_path.display()),
-                                source_ranges: vec![source_range],
-                            })
+                            KclError::Semantic(KclErrorDetails::new(
+                                format!("Could not get the parent path of the file `{}`", file_path.display()),
+                                vec![source_range],
+                            ))
                         })?;
 
-                        let bin_contents = ctxt.fs.read(&bin_path, source_range).await.map_err(|e| {
-                            KclError::Semantic(KclErrorDetails {
-                                message: e.to_string(),
-                                source_ranges: vec![source_range],
-                            })
+                        let bin_contents =
+                            ctxt.fs.read(&bin_path, source_range).await.map_err(|e| {
+                                KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range]))
                             })?;
 
                         import_files.push(ImportFile {
@@ -157,13 +141,13 @@ pub(super) fn format_from_annotations(
         if p.key.name == annotations::IMPORT_FORMAT {
             result = Some(
                 get_import_format_from_extension(annotations::expect_ident(&p.value)?).map_err(|_| {
-                    KclError::Semantic(KclErrorDetails {
-                        message: format!(
+                    KclError::Semantic(KclErrorDetails::new(
+                        format!(
                             "Unknown format for import, expected one of: {}",
                             crate::IMPORT_FILE_EXTENSIONS.join(", ")
                         ),
-                        source_ranges: vec![p.as_source_range()],
-                    })
+                        vec![p.as_source_range()],
+                    ))
                 })?,
             );
             break;
@@ -175,10 +159,10 @@ pub(super) fn format_from_annotations(
             path.extension()
                 .and_then(|ext| get_import_format_from_extension(ext).ok())
         })
-        .ok_or(KclError::Semantic(KclErrorDetails {
-            message: "Unknown or missing extension, and no specified format for imported file".to_owned(),
-            source_ranges: vec![import_source_range],
-        }))?;
+        .ok_or(KclError::Semantic(KclErrorDetails::new(
+            "Unknown or missing extension, and no specified format for imported file".to_owned(),
+            vec![import_source_range],
+        )))?;
 
     for p in props {
         match p.key.name.as_str() {
@@ -190,15 +174,15 @@ pub(super) fn format_from_annotations(
             }
             annotations::IMPORT_FORMAT => {}
             _ => {
-                return Err(KclError::Semantic(KclErrorDetails {
-                    message: format!(
+                return Err(KclError::Semantic(KclErrorDetails::new(
+                    format!(
                         "Unexpected annotation for import, expected one of: {}, {}, {}",
                         annotations::IMPORT_FORMAT,
                         annotations::IMPORT_COORDS,
                         annotations::IMPORT_LENGTH_UNIT
                     ),
-                    source_ranges: vec![p.as_source_range()],
-                }))
+                    vec![p.as_source_range()],
+                )))
             }
         }
     }
@@ -215,8 +199,8 @@ fn set_coords(fmt: &mut InputFormat3d, coords_str: &str, source_range: SourceRan
     }
 
     let Some(coords) = coords else {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message: format!(
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            format!(
                 "Unknown coordinate system: {coords_str}, expected one of: {}",
                 annotations::IMPORT_COORDS_VALUES
                     .iter()
@@ -224,8 +208,8 @@ fn set_coords(fmt: &mut InputFormat3d, coords_str: &str, source_range: SourceRan
                     .collect::<Vec<_>>()
                     .join(", ")
             ),
-            source_ranges: vec![source_range],
-        }));
+            vec![source_range],
+        )));
     };
 
     match fmt {
@@ -233,13 +217,13 @@ fn set_coords(fmt: &mut InputFormat3d, coords_str: &str, source_range: SourceRan
         InputFormat3d::Ply(opts) => opts.coords = coords,
         InputFormat3d::Stl(opts) => opts.coords = coords,
         _ => {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!(
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "`{}` option cannot be applied to the specified format",
                     annotations::IMPORT_COORDS
                 ),
-                source_ranges: vec![source_range],
-            }))
+                vec![source_range],
+            )))
         }
     }
 
@@ -254,13 +238,13 @@ fn set_length_unit(fmt: &mut InputFormat3d, units_str: &str, source_range: Sourc
         InputFormat3d::Ply(opts) => opts.units = units.into(),
         InputFormat3d::Stl(opts) => opts.units = units.into(),
         _ => {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!(
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "`{}` option cannot be applied to the specified format",
                     annotations::IMPORT_LENGTH_UNIT
                 ),
-                source_ranges: vec![source_range],
-            }))
+                vec![source_range],
+            )))
         }
     }
 

rust/kcl-lib/src/execution/kcl_value.rs

@@ -543,17 +543,13 @@ impl KclValue {
     /// If this value fits in a u32, return it.
     pub fn get_u32(&self, source_ranges: Vec<SourceRange>) -> Result<u32, KclError> {
         let u = self.as_int().and_then(|n| u64::try_from(n).ok()).ok_or_else(|| {
-            KclError::Semantic(KclErrorDetails {
-                message: "Expected an integer >= 0".to_owned(),
-                source_ranges: source_ranges.clone(),
-            })
+            KclError::Semantic(KclErrorDetails::new(
+                "Expected an integer >= 0".to_owned(),
+                source_ranges.clone(),
+            ))
         })?;
-        u32::try_from(u).map_err(|_| {
-            KclError::Semantic(KclErrorDetails {
-                message: "Number was too big".to_owned(),
-                source_ranges,
-            })
-        })
+        u32::try_from(u)
+            .map_err(|_| KclError::Semantic(KclErrorDetails::new("Number was too big".to_owned(), source_ranges)))
     }
 
     /// If this value is of type function, return it.
@@ -568,10 +564,10 @@ impl KclValue {
     pub fn get_tag_identifier(&self) -> Result<TagIdentifier, KclError> {
         match self {
             KclValue::TagIdentifier(t) => Ok(*t.clone()),
-            _ => Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Not a tag identifier: {:?}", self),
-                source_ranges: self.clone().into(),
-            })),
+            _ => Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Not a tag identifier: {:?}", self),
+                self.clone().into(),
+            ))),
         }
     }
 
@@ -579,20 +575,20 @@ impl KclValue {
     pub fn get_tag_declarator(&self) -> Result<TagNode, KclError> {
         match self {
             KclValue::TagDeclarator(t) => Ok((**t).clone()),
-            _ => Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Not a tag declarator: {:?}", self),
-                source_ranges: self.clone().into(),
-            })),
+            _ => Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Not a tag declarator: {:?}", self),
+                self.clone().into(),
+            ))),
         }
     }
 
     /// If this KCL value is a bool, retrieve it.
     pub fn get_bool(&self) -> Result<bool, KclError> {
         let Self::Bool { value: b, .. } = self else {
-            return Err(KclError::Type(KclErrorDetails {
-                source_ranges: self.into(),
-                message: format!("Expected bool, found {}", self.human_friendly_type()),
-            }));
+            return Err(KclError::Type(KclErrorDetails::new(
+                format!("Expected bool, found {}", self.human_friendly_type()),
+                self.into(),
+            )));
         };
         Ok(*b)
     }

rust/kcl-lib/src/execution/memory.rs

@@ -364,10 +364,10 @@ impl ProgramMemory {
             };
         }
 
-        Err(KclError::UndefinedValue(KclErrorDetails {
-            message: format!("`{}` is not defined", var),
-            source_ranges: vec![source_range],
-        }))
+        Err(KclError::UndefinedValue(KclErrorDetails::new(
+            format!("`{}` is not defined", var),
+            vec![source_range],
+        )))
     }
 
     /// Iterate over all key/value pairs in the specified environment which satisfy the provided
@@ -485,10 +485,10 @@ impl ProgramMemory {
             };
         }
 
-        Err(KclError::UndefinedValue(KclErrorDetails {
-            message: format!("`{}` is not defined", var),
-            source_ranges: vec![],
-        }))
+        Err(KclError::UndefinedValue(KclErrorDetails::new(
+            format!("`{}` is not defined", var),
+            vec![],
+        )))
     }
 }
 
@@ -643,10 +643,10 @@ impl Stack {
     pub fn add(&mut self, key: String, value: KclValue, source_range: SourceRange) -> Result<(), KclError> {
         let env = self.memory.get_env(self.current_env.index());
         if env.contains_key(&key) {
-            return Err(KclError::ValueAlreadyDefined(KclErrorDetails {
-                message: format!("Cannot redefine `{}`", key),
-                source_ranges: vec![source_range],
-            }));
+            return Err(KclError::ValueAlreadyDefined(KclErrorDetails::new(
+                format!("Cannot redefine `{}`", key),
+                vec![source_range],
+            )));
         }
 
         self.memory.stats.mutation_count.fetch_add(1, Ordering::Relaxed);

rust/kcl-lib/src/execution/mod.rs

@@ -858,10 +858,9 @@ impl ExecutorContext {
 
             for module in modules {
                 let Some((import_stmt, module_id, module_path, repr)) = universe.get(&module) else {
-                    return Err(KclErrorWithOutputs::no_outputs(KclError::Internal(KclErrorDetails {
-                        message: format!("Module {module} not found in universe"),
-                        source_ranges: Default::default(),
-                    })));
+                    return Err(KclErrorWithOutputs::no_outputs(KclError::Internal(
+                        KclErrorDetails::new(format!("Module {module} not found in universe"), Default::default()),
+                    )));
                 };
                 let module_id = *module_id;
                 let module_path = module_path.clone();
@@ -921,10 +920,10 @@ impl ExecutorContext {
 
                             result.map(|val| ModuleRepr::Foreign(geom.clone(), val))
                         }
-                        ModuleRepr::Dummy | ModuleRepr::Root => Err(KclError::Internal(KclErrorDetails {
-                            message: format!("Module {module_path} not found in universe"),
-                            source_ranges: vec![source_range],
-                        })),
+                        ModuleRepr::Dummy | ModuleRepr::Root => Err(KclError::Internal(KclErrorDetails::new(
+                            format!("Module {module_path} not found in universe"),
+                            vec![source_range],
+                        ))),
                     }
                 };
 
@@ -1288,10 +1287,10 @@ impl ExecutorContext {
             .await?;
 
         let kittycad_modeling_cmds::websocket::OkWebSocketResponseData::Export { files } = resp else {
-            return Err(KclError::Internal(crate::errors::KclErrorDetails {
-                message: format!("Expected Export response, got {resp:?}",),
-                source_ranges: vec![SourceRange::default()],
-            }));
+            return Err(KclError::Internal(crate::errors::KclErrorDetails::new(
+                format!("Expected Export response, got {resp:?}",),
+                vec![SourceRange::default()],
+            )));
         };
 
         Ok(files)
@@ -1308,10 +1307,10 @@ impl ExecutorContext {
                     coords: *kittycad_modeling_cmds::coord::KITTYCAD,
                     created: if deterministic_time {
                         Some("2021-01-01T00:00:00Z".parse().map_err(|e| {
-                            KclError::Internal(crate::errors::KclErrorDetails {
-                                message: format!("Failed to parse date: {}", e),
-                                source_ranges: vec![SourceRange::default()],
-                            })
+                            KclError::Internal(crate::errors::KclErrorDetails::new(
+                                format!("Failed to parse date: {}", e),
+                                vec![SourceRange::default()],
+                            ))
                         })?)
                     } else {
                         None
@@ -1388,10 +1387,10 @@ pub(crate) async fn parse_execute_with_project_dir(
     let exec_ctxt = ExecutorContext {
         engine: Arc::new(Box::new(
             crate::engine::conn_mock::EngineConnection::new().await.map_err(|err| {
-                KclError::Internal(crate::errors::KclErrorDetails {
-                    message: format!("Failed to create mock engine connection: {}", err),
-                    source_ranges: vec![SourceRange::default()],
-                })
+                KclError::Internal(crate::errors::KclErrorDetails::new(
+                    format!("Failed to create mock engine connection: {}", err),
+                    vec![SourceRange::default()],
+                ))
             })?,
         )),
         fs: Arc::new(crate::fs::FileManager::new()),
@@ -1804,10 +1803,10 @@ foo
         let err = result.unwrap_err();
         assert_eq!(
             err,
-            KclError::Syntax(KclErrorDetails {
-                message: "Unexpected token: #".to_owned(),
-                source_ranges: vec![SourceRange::new(14, 15, ModuleId::default())],
-            }),
+            KclError::Syntax(KclErrorDetails::new(
+                "Unexpected token: #".to_owned(),
+                vec![SourceRange::new(14, 15, ModuleId::default())],
+            )),
         );
     }
 
@@ -2063,10 +2062,10 @@ notTagIdentifier = !myTag";
             // TODO: We don't currently parse this, but we should.  It should be
             // a runtime error instead.
             parse_execute(code10).await.unwrap_err(),
-            KclError::Syntax(KclErrorDetails {
-                message: "Unexpected token: !".to_owned(),
-                source_ranges: vec![SourceRange::new(10, 11, ModuleId::default())],
-            })
+            KclError::Syntax(KclErrorDetails::new(
+                "Unexpected token: !".to_owned(),
+                vec![SourceRange::new(10, 11, ModuleId::default())],
+            ))
         );
 
         let code11 = "
@@ -2076,10 +2075,10 @@ notPipeSub = 1 |> identity(!%))";
             // TODO: We don't currently parse this, but we should.  It should be
             // a runtime error instead.
             parse_execute(code11).await.unwrap_err(),
-            KclError::Syntax(KclErrorDetails {
-                message: "Unexpected token: |>".to_owned(),
-                source_ranges: vec![SourceRange::new(44, 46, ModuleId::default())],
-            })
+            KclError::Syntax(KclErrorDetails::new(
+                "Unexpected token: |>".to_owned(),
+                vec![SourceRange::new(44, 46, ModuleId::default())],
+            ))
         );
 
         // TODO: Add these tests when we support these types.

rust/kcl-lib/src/execution/state.rs

@@ -276,8 +276,8 @@ impl ExecState {
     }
 
     pub(super) fn circular_import_error(&self, path: &ModulePath, source_range: SourceRange) -> KclError {
-        KclError::ImportCycle(KclErrorDetails {
-            message: format!(
+        KclError::ImportCycle(KclErrorDetails::new(
+            format!(
                 "circular import of modules is not allowed: {} -> {}",
                 self.global
                     .mod_loader
@@ -288,8 +288,8 @@ impl ExecState {
                     .join(" -> "),
                 path,
             ),
-            source_ranges: vec![source_range],
-        })
+            vec![source_range],
+        ))
     }
 
     pub(crate) fn pipe_value(&self) -> Option<&KclValue> {
@@ -389,14 +389,14 @@ impl MetaSettings {
                     self.kcl_version = value;
                 }
                 name => {
-                    return Err(KclError::Semantic(KclErrorDetails {
-                        message: format!(
+                    return Err(KclError::Semantic(KclErrorDetails::new(
+                        format!(
                             "Unexpected settings key: `{name}`; expected one of `{}`, `{}`",
                             annotations::SETTINGS_UNIT_LENGTH,
                             annotations::SETTINGS_UNIT_ANGLE
                         ),
-                        source_ranges: vec![annotation.as_source_range()],
-                    }))
+                        vec![annotation.as_source_range()],
+                    )))
                 }
             }
         }

rust/kcl-lib/src/fs/local.rs

@@ -28,19 +28,19 @@ impl Default for FileManager {
 impl FileSystem for FileManager {
     async fn read(&self, path: &TypedPath, source_range: SourceRange) -> Result<Vec<u8>, KclError> {
         tokio::fs::read(&path.0).await.map_err(|e| {
-            KclError::Io(KclErrorDetails {
-                message: format!("Failed to read file `{}`: {}", path.display(), e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Io(KclErrorDetails::new(
+                format!("Failed to read file `{}`: {}", path.display(), e),
+                vec![source_range],
+            ))
         })
     }
 
     async fn read_to_string(&self, path: &TypedPath, source_range: SourceRange) -> Result<String, KclError> {
         tokio::fs::read_to_string(&path.0).await.map_err(|e| {
-            KclError::Io(KclErrorDetails {
-                message: format!("Failed to read file `{}`: {}", path.display(), e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Io(KclErrorDetails::new(
+                format!("Failed to read file `{}`: {}", path.display(), e),
+                vec![source_range],
+            ))
         })
     }
 
@@ -49,10 +49,10 @@ impl FileSystem for FileManager {
             if e.kind() == std::io::ErrorKind::NotFound {
                 Ok(false)
             } else {
-                Err(KclError::Io(KclErrorDetails {
-                    message: format!("Failed to check if file `{}` exists: {}", path.display(), e),
-                    source_ranges: vec![source_range],
-                }))
+                Err(KclError::Io(KclErrorDetails::new(
+                    format!("Failed to check if file `{}` exists: {}", path.display(), e),
+                    vec![source_range],
+                )))
             }
         })
     }
@@ -71,10 +71,10 @@ impl FileSystem for FileManager {
             }
 
             let mut read_dir = tokio::fs::read_dir(&path).await.map_err(|e| {
-                KclError::Io(KclErrorDetails {
-                    message: format!("Failed to read directory `{}`: {}", path.display(), e),
-                    source_ranges: vec![source_range],
-                })
+                KclError::Io(KclErrorDetails::new(
+                    format!("Failed to read directory `{}`: {}", path.display(), e),
+                    vec![source_range],
+                ))
             })?;
 
             while let Ok(Some(entry)) = read_dir.next_entry().await {

rust/kcl-lib/src/fs/wasm.rs

@@ -46,18 +46,16 @@ unsafe impl Sync for FileManager {}
 #[async_trait::async_trait]
 impl FileSystem for FileManager {
     async fn read(&self, path: &TypedPath, source_range: SourceRange) -> Result<Vec<u8>, KclError> {
-        let promise = self.manager.read_file(path.to_string_lossy()).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: e.to_string().into(),
-                source_ranges: vec![source_range],
-            })
-        })?;
+        let promise = self
+            .manager
+            .read_file(path.to_string_lossy())
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
 
         let value = JsFuture::from(promise).await.map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to wait for promise from engine: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to wait for promise from engine: {:?}", e),
+                vec![source_range],
+            ))
         })?;
 
         let array = js_sys::Uint8Array::new(&value);
@@ -69,35 +67,33 @@ impl FileSystem for FileManager {
     async fn read_to_string(&self, path: &TypedPath, source_range: SourceRange) -> Result<String, KclError> {
         let bytes = self.read(path, source_range).await?;
         let string = String::from_utf8(bytes).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to convert bytes to string: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to convert bytes to string: {:?}", e),
+                vec![source_range],
+            ))
         })?;
 
         Ok(string)
     }
 
     async fn exists(&self, path: &TypedPath, source_range: SourceRange) -> Result<bool, crate::errors::KclError> {
-        let promise = self.manager.exists(path.to_string_lossy()).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: e.to_string().into(),
-                source_ranges: vec![source_range],
-            })
-        })?;
+        let promise = self
+            .manager
+            .exists(path.to_string_lossy())
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
 
         let value = JsFuture::from(promise).await.map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to wait for promise from engine: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to wait for promise from engine: {:?}", e),
+                vec![source_range],
+            ))
         })?;
 
         let it_exists = value.as_bool().ok_or_else(|| {
-            KclError::Engine(KclErrorDetails {
-                message: "Failed to convert value to bool".to_string(),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                "Failed to convert value to bool".to_string(),
+                vec![source_range],
+            ))
         })?;
 
         Ok(it_exists)
@@ -108,32 +104,30 @@ impl FileSystem for FileManager {
         path: &TypedPath,
         source_range: SourceRange,
     ) -> Result<Vec<TypedPath>, crate::errors::KclError> {
-        let promise = self.manager.get_all_files(path.to_string_lossy()).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: e.to_string().into(),
-                source_ranges: vec![source_range],
-            })
-        })?;
+        let promise = self
+            .manager
+            .get_all_files(path.to_string_lossy())
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
 
         let value = JsFuture::from(promise).await.map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to wait for promise from javascript: {:?}", e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to wait for promise from javascript: {:?}", e),
+                vec![source_range],
+            ))
         })?;
 
         let s = value.as_string().ok_or_else(|| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to get string from response from javascript: `{:?}`", value),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to get string from response from javascript: `{:?}`", value),
+                vec![source_range],
+            ))
         })?;
 
         let files: Vec<String> = serde_json::from_str(&s).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
-                message: format!("Failed to parse json from javascript: `{}` `{:?}`", s, e),
-                source_ranges: vec![source_range],
-            })
+            KclError::Engine(KclErrorDetails::new(
+                format!("Failed to parse json from javascript: `{}` `{:?}`", s, e),
+                vec![source_range],
+            ))
         })?;
 
         Ok(files.into_iter().map(|s| TypedPath::from(&s)).collect())

rust/kcl-lib/src/lib.rs

@@ -86,7 +86,8 @@ mod wasm;
 pub use coredump::CoreDump;
 pub use engine::{AsyncTasks, EngineManager, EngineStats};
 pub use errors::{
-    CompilationError, ConnectionError, ExecError, KclError, KclErrorWithOutputs, Report, ReportWithOutputs,
+    BacktraceItem, CompilationError, ConnectionError, ExecError, KclError, KclErrorWithOutputs, Report,
+    ReportWithOutputs,
 };
 pub use execution::{
     bust_cache, clear_mem_cache,

rust/kcl-lib/src/modules.rs

@@ -58,8 +58,8 @@ impl ModuleLoader {
     }
 
     pub(crate) fn import_cycle_error(&self, path: &ModulePath, source_range: SourceRange) -> KclError {
-        KclError::ImportCycle(KclErrorDetails {
-            message: format!(
+        KclError::ImportCycle(KclErrorDetails::new(
+            format!(
                 "circular import of modules is not allowed: {} -> {}",
                 self.import_stack
                     .iter()
@@ -68,8 +68,8 @@ impl ModuleLoader {
                     .join(" -> "),
                 path,
             ),
-            source_ranges: vec![source_range],
-        })
+            vec![source_range],
+        ))
     }
 
     pub(crate) fn enter_module(&mut self, path: &ModulePath) {
@@ -169,10 +169,10 @@ impl ModulePath {
             ModulePath::Std { value: name } => Ok(ModuleSource {
                 source: read_std(name)
                     .ok_or_else(|| {
-                        KclError::Semantic(KclErrorDetails {
-                            message: format!("Cannot find standard library module to import: std::{name}."),
-                            source_ranges: vec![source_range],
-                        })
+                        KclError::Semantic(KclErrorDetails::new(
+                            format!("Cannot find standard library module to import: std::{name}."),
+                            vec![source_range],
+                        ))
                     })
                     .map(str::to_owned)?,
                 path: self.clone(),

rust/kcl-lib/src/parsing/mod.rs

@@ -51,7 +51,7 @@ pub fn parse_tokens(mut tokens: TokenStream) -> ParseResult {
         } else {
             format!("found unknown tokens [{}]", token_list.join(", "))
         };
-        return KclError::Lexical(KclErrorDetails { source_ranges, message }).into();
+        return KclError::Lexical(KclErrorDetails::new(message, source_ranges)).into();
     }
 
     // Important, to not call this before the unknown tokens check.

rust/kcl-lib/src/parsing/token/mod.rs

@@ -578,10 +578,10 @@ impl From<ParseError<Input<'_>, winnow::error::ContextError>> for KclError {
             // This is an offset, not an index, and may point to
             // the end of input (input.len()) on eof errors.
 
-            return KclError::Lexical(crate::errors::KclErrorDetails {
-                source_ranges: vec![SourceRange::new(offset, offset, module_id)],
-                message: "unexpected EOF while parsing".to_string(),
-            });
+            return KclError::Lexical(crate::errors::KclErrorDetails::new(
+                "unexpected EOF while parsing".to_owned(),
+                vec![SourceRange::new(offset, offset, module_id)],
+            ));
         }
 
         // TODO: Add the Winnow tokenizer context to the error.
@@ -589,9 +589,9 @@ impl From<ParseError<Input<'_>, winnow::error::ContextError>> for KclError {
         let bad_token = &input[offset];
         // TODO: Add the Winnow parser context to the error.
         // See https://github.com/KittyCAD/modeling-app/issues/784
-        KclError::Lexical(crate::errors::KclErrorDetails {
-            source_ranges: vec![SourceRange::new(offset, offset + 1, module_id)],
-            message: format!("found unknown token '{}'", bad_token),
-        })
+        KclError::Lexical(crate::errors::KclErrorDetails::new(
+            format!("found unknown token '{}'", bad_token),
+            vec![SourceRange::new(offset, offset + 1, module_id)],
+        ))
     }
 }

rust/kcl-lib/src/std/appearance.rs

@@ -32,10 +32,10 @@ pub async fn appearance(exec_state: &mut ExecState, args: Args) -> Result<KclVal
 
     // Make sure the color if set is valid.
     if !HEX_REGEX.is_match(&color) {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message: format!("Invalid hex color (`{}`), try something like `#fff000`", color),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            format!("Invalid hex color (`{}`), try something like `#fff000`", color),
+            vec![args.source_range],
+        )));
     }
 
     let result = inner_appearance(
@@ -282,10 +282,10 @@ async fn inner_appearance(
     for solid_id in solids.ids(&args.ctx).await? {
         // Set the material properties.
         let rgb = rgba_simple::RGB::<f32>::from_hex(&color).map_err(|err| {
-            KclError::Semantic(KclErrorDetails {
-                message: format!("Invalid hex color (`{color}`): {err}"),
-                source_ranges: vec![args.source_range],
-            })
+            KclError::Semantic(KclErrorDetails::new(
+                format!("Invalid hex color (`{color}`): {err}"),
+                vec![args.source_range],
+            ))
         })?;
 
         let color = Color {

rust/kcl-lib/src/std/args.rs

@@ -122,14 +122,14 @@ impl Args {
         }
 
         T::from_kcl_val(&arg.value).map(Some).ok_or_else(|| {
-            KclError::Type(KclErrorDetails {
-                source_ranges: vec![self.source_range],
-                message: format!(
+            KclError::Type(KclErrorDetails::new(
+                format!(
                     "The arg {label} was given, but it was the wrong type. It should be type {} but it was {}",
                     tynm::type_name::<T>(),
                     arg.value.human_friendly_type(),
                 ),
-            })
+                vec![self.source_range],
+            ))
         })
     }
 
@@ -155,10 +155,10 @@ impl Args {
         T: FromKclValue<'a>,
     {
         self.get_kw_arg_opt(label)?.ok_or_else(|| {
-            KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![self.source_range],
-                message: format!("This function requires a keyword argument '{label}'"),
-            })
+            KclError::Semantic(KclErrorDetails::new(
+                format!("This function requires a keyword argument '{label}'"),
+                vec![self.source_range],
+            ))
         })
     }
 
@@ -172,10 +172,10 @@ impl Args {
         T: for<'a> FromKclValue<'a>,
     {
         let Some(arg) = self.kw_args.labeled.get(label) else {
-            return Err(KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![self.source_range],
-                message: format!("This function requires a keyword argument '{label}'"),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("This function requires a keyword argument '{label}'"),
+                vec![self.source_range],
+            )));
         };
 
         let arg = arg.value.coerce(ty, exec_state).map_err(|_| {
@@ -206,10 +206,7 @@ impl Args {
             if message.contains("one or more Solids or imported geometry but it's actually of type Sketch") {
                 message = format!("{message}. {ERROR_STRING_SKETCH_TO_SOLID_HELPER}");
             }
-            KclError::Semantic(KclErrorDetails {
-                source_ranges: arg.source_ranges(),
-                message,
-            })
+            KclError::Semantic(KclErrorDetails::new(message, arg.source_ranges()))
         })?;
 
         // TODO unnecessary cloning
@@ -223,21 +220,21 @@ impl Args {
         T: FromKclValue<'a>,
     {
         let Some(arg) = self.kw_args.labeled.get(label) else {
-            let err = KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![self.source_range],
-                message: format!("This function requires a keyword argument '{label}'"),
-            });
+            let err = KclError::Semantic(KclErrorDetails::new(
+                format!("This function requires a keyword argument '{label}'"),
+                vec![self.source_range],
+            ));
             return Err(err);
         };
         let Some(array) = arg.value.as_array() else {
-            let err = KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![arg.source_range],
-                message: format!(
+            let err = KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "Expected an array of {} but found {}",
                     tynm::type_name::<T>(),
                     arg.value.human_friendly_type()
                 ),
-            });
+                vec![arg.source_range],
+            ));
             return Err(err);
         };
         array
@@ -245,14 +242,14 @@ impl Args {
             .map(|item| {
                 let source = SourceRange::from(item);
                 let val = FromKclValue::from_kcl_val(item).ok_or_else(|| {
-                    KclError::Semantic(KclErrorDetails {
-                        source_ranges: arg.source_ranges(),
-                        message: format!(
+                    KclError::Semantic(KclErrorDetails::new(
+                        format!(
                             "Expected a {} but found {}",
                             tynm::type_name::<T>(),
                             arg.value.human_friendly_type()
                         ),
-                    })
+                        arg.source_ranges(),
+                    ))
                 })?;
                 Ok((val, source))
             })
@@ -267,19 +264,19 @@ impl Args {
     {
         let arg = self
             .unlabeled_kw_arg_unconverted()
-            .ok_or(KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![self.source_range],
-                message: format!("This function requires a value for the special unlabeled first parameter, '{label}'"),
-            }))?;
+            .ok_or(KclError::Semantic(KclErrorDetails::new(
+                format!("This function requires a value for the special unlabeled first parameter, '{label}'"),
+                vec![self.source_range],
+            )))?;
 
         T::from_kcl_val(&arg.value).ok_or_else(|| {
             let expected_type_name = tynm::type_name::<T>();
             let actual_type_name = arg.value.human_friendly_type();
             let message = format!("This function expected the input argument to be of type {expected_type_name} but it's actually of type {actual_type_name}");
-            KclError::Semantic(KclErrorDetails {
-                source_ranges: arg.source_ranges(),
+            KclError::Semantic(KclErrorDetails::new(
                 message,
-            })
+                arg.source_ranges(),
+            ))
         })
     }
 
@@ -296,10 +293,10 @@ impl Args {
     {
         let arg = self
             .unlabeled_kw_arg_unconverted()
-            .ok_or(KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![self.source_range],
-                message: format!("This function requires a value for the special unlabeled first parameter, '{label}'"),
-            }))?;
+            .ok_or(KclError::Semantic(KclErrorDetails::new(
+                format!("This function requires a value for the special unlabeled first parameter, '{label}'"),
+                vec![self.source_range],
+            )))?;
 
         let arg = arg.value.coerce(ty, exec_state).map_err(|_| {
             let actual_type = arg.value.principal_type();
@@ -330,17 +327,14 @@ impl Args {
             if message.contains("one or more Solids or imported geometry but it's actually of type Sketch") {
                 message = format!("{message}. {ERROR_STRING_SKETCH_TO_SOLID_HELPER}");
             }
-            KclError::Semantic(KclErrorDetails {
-                source_ranges: arg.source_ranges(),
-                message,
-            })
+            KclError::Semantic(KclErrorDetails::new(message, arg.source_ranges()))
         })?;
 
         T::from_kcl_val(&arg).ok_or_else(|| {
-            KclError::Internal(KclErrorDetails {
-                source_ranges: vec![self.source_range],
-                message: "Mismatch between type coercion and value extraction (this isn't your fault).\nTo assist in bug-reporting, expected type: {ty:?}; actual value: {arg:?}".to_owned(),
-           })
+            KclError::Internal(KclErrorDetails::new(
+                "Mismatch between type coercion and value extraction (this isn't your fault).\nTo assist in bug-reporting, expected type: {ty:?}; actual value: {arg:?}".to_owned(),
+                vec![self.source_range],
+           ))
         })
     }
 
@@ -383,17 +377,17 @@ impl Args {
             exec_state.stack().get_from_call_stack(&tag.value, self.source_range)?
         {
             let info = t.get_info(epoch).ok_or_else(|| {
-                KclError::Type(KclErrorDetails {
-                    message: format!("Tag `{}` does not have engine info", tag.value),
-                    source_ranges: vec![self.source_range],
-                })
+                KclError::Type(KclErrorDetails::new(
+                    format!("Tag `{}` does not have engine info", tag.value),
+                    vec![self.source_range],
+                ))
             })?;
             Ok(info)
         } else {
-            Err(KclError::Type(KclErrorDetails {
-                message: format!("Tag `{}` does not exist", tag.value),
-                source_ranges: vec![self.source_range],
-            }))
+            Err(KclError::Type(KclErrorDetails::new(
+                format!("Tag `{}` does not exist", tag.value),
+                vec![self.source_range],
+            )))
         }
     }
 
@@ -522,19 +516,19 @@ impl Args {
         must_be_planar: bool,
     ) -> Result<uuid::Uuid, KclError> {
         if tag.value.is_empty() {
-            return Err(KclError::Type(KclErrorDetails {
-                message: "Expected a non-empty tag for the face".to_string(),
-                source_ranges: vec![self.source_range],
-            }));
+            return Err(KclError::Type(KclErrorDetails::new(
+                "Expected a non-empty tag for the face".to_string(),
+                vec![self.source_range],
+            )));
         }
 
         let engine_info = self.get_tag_engine_info_check_surface(exec_state, tag)?;
 
         let surface = engine_info.surface.as_ref().ok_or_else(|| {
-            KclError::Type(KclErrorDetails {
-                message: format!("Tag `{}` does not have a surface", tag.value),
-                source_ranges: vec![self.source_range],
-            })
+            KclError::Type(KclErrorDetails::new(
+                format!("Tag `{}` does not have a surface", tag.value),
+                vec![self.source_range],
+            ))
         })?;
 
         if let Some(face_from_surface) = match surface {
@@ -550,10 +544,10 @@ impl Args {
                 }
             }
             // The must be planar check must be called before the arc check.
-            ExtrudeSurface::ExtrudeArc(_) if must_be_planar => Some(Err(KclError::Type(KclErrorDetails {
-                message: format!("Tag `{}` is a non-planar surface", tag.value),
-                source_ranges: vec![self.source_range],
-            }))),
+            ExtrudeSurface::ExtrudeArc(_) if must_be_planar => Some(Err(KclError::Type(KclErrorDetails::new(
+                format!("Tag `{}` is a non-planar surface", tag.value),
+                vec![self.source_range],
+            )))),
             ExtrudeSurface::ExtrudeArc(extrude_arc) => {
                 if let Some(arc_tag) = &extrude_arc.tag {
                     if arc_tag.name == tag.value {
@@ -577,10 +571,10 @@ impl Args {
                 }
             }
             // The must be planar check must be called before the fillet check.
-            ExtrudeSurface::Fillet(_) if must_be_planar => Some(Err(KclError::Type(KclErrorDetails {
-                message: format!("Tag `{}` is a non-planar surface", tag.value),
-                source_ranges: vec![self.source_range],
-            }))),
+            ExtrudeSurface::Fillet(_) if must_be_planar => Some(Err(KclError::Type(KclErrorDetails::new(
+                format!("Tag `{}` is a non-planar surface", tag.value),
+                vec![self.source_range],
+            )))),
             ExtrudeSurface::Fillet(fillet) => {
                 if let Some(fillet_tag) = &fillet.tag {
                     if fillet_tag.name == tag.value {
@@ -597,10 +591,10 @@ impl Args {
         }
 
         // If we still haven't found the face, return an error.
-        Err(KclError::Type(KclErrorDetails {
-            message: format!("Expected a face with the tag `{}`", tag.value),
-            source_ranges: vec![self.source_range],
-        }))
+        Err(KclError::Type(KclErrorDetails::new(
+            format!("Expected a face with the tag `{}`", tag.value),
+            vec![self.source_range],
+        )))
     }
 }
 
@@ -622,20 +616,20 @@ where
 {
     fn from_args(args: &'a Args, i: usize) -> Result<Self, KclError> {
         let Some(arg) = args.args.get(i) else {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Expected an argument at index {i}"),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Expected an argument at index {i}"),
+                vec![args.source_range],
+            )));
         };
         let Some(val) = T::from_kcl_val(&arg.value) else {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!(
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "Argument at index {i} was supposed to be type {} but found {}",
                     tynm::type_name::<T>(),
                     arg.value.human_friendly_type(),
                 ),
-                source_ranges: arg.source_ranges(),
-            }));
+                arg.source_ranges(),
+            )));
         };
         Ok(val)
     }
@@ -651,14 +645,14 @@ where
             return Ok(None);
         }
         let Some(val) = T::from_kcl_val(&arg.value) else {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!(
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "Argument at index {i} was supposed to be type Option<{}> but found {}",
                     tynm::type_name::<T>(),
                     arg.value.human_friendly_type()
                 ),
-                source_ranges: arg.source_ranges(),
-            }));
+                arg.source_ranges(),
+            )));
         };
         Ok(Some(val))
     }

rust/kcl-lib/src/std/array.rs

@@ -58,10 +58,10 @@ async fn call_map_closure(
     let output = map_fn.call_kw(None, exec_state, ctxt, args, source_range).await?;
     let source_ranges = vec![source_range];
     let output = output.ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
-            message: "Map function must return a value".to_string(),
+        KclError::Semantic(KclErrorDetails::new(
+            "Map function must return a value".to_owned(),
             source_ranges,
-        })
+        ))
     })?;
     Ok(output)
 }
@@ -118,10 +118,10 @@ async fn call_reduce_closure(
     // Unpack the returned transform object.
     let source_ranges = vec![source_range];
     let out = transform_fn_return.ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
-            message: "Reducer function must return a value".to_string(),
-            source_ranges: source_ranges.clone(),
-        })
+        KclError::Semantic(KclErrorDetails::new(
+            "Reducer function must return a value".to_string(),
+            source_ranges.clone(),
+        ))
     })?;
     Ok(out)
 }
@@ -133,10 +133,10 @@ pub async fn push(_exec_state: &mut ExecState, args: Args) -> Result<KclValue, K
     let KclValue::HomArray { value: values, ty } = array else {
         let meta = vec![args.source_range];
         let actual_type = array.human_friendly_type();
-        return Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: meta,
-            message: format!("You can't push to a value of type {actual_type}, only an array"),
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            format!("You can't push to a value of type {actual_type}, only an array"),
+            meta,
+        )));
     };
     let ty = if item.has_type(&ty) {
         ty
@@ -161,10 +161,10 @@ pub async fn pop(_exec_state: &mut ExecState, args: Args) -> Result<KclValue, Kc
     let KclValue::HomArray { value: values, ty } = array else {
         let meta = vec![args.source_range];
         let actual_type = array.human_friendly_type();
-        return Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: meta,
-            message: format!("You can't pop from a value of type {actual_type}, only an array"),
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            format!("You can't pop from a value of type {actual_type}, only an array"),
+            meta,
+        )));
     };
 
     let new_array = inner_pop(values, &args)?;
@@ -173,10 +173,10 @@ pub async fn pop(_exec_state: &mut ExecState, args: Args) -> Result<KclValue, Kc
 
 fn inner_pop(array: Vec<KclValue>, args: &Args) -> Result<Vec<KclValue>, KclError> {
     if array.is_empty() {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message: "Cannot pop from an empty array".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            "Cannot pop from an empty array".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     // Create a new array with all elements except the last one

rust/kcl-lib/src/std/assert.rs

@@ -12,10 +12,10 @@ use crate::{
 
 async fn _assert(value: bool, message: &str, args: &Args) -> Result<(), KclError> {
     if !value {
-        return Err(KclError::Type(KclErrorDetails {
-            message: format!("assert failed: {}", message),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            format!("assert failed: {}", message),
+            vec![args.source_range],
+        )));
     }
     Ok(())
 }
@@ -111,19 +111,18 @@ async fn inner_assert(
     .iter()
     .all(|cond| cond.is_none());
     if no_condition_given {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "You must provide at least one condition in this assert (for example, isEqualTo)".to_owned(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "You must provide at least one condition in this assert (for example, isEqualTo)".to_owned(),
+            vec![args.source_range],
+        )));
     }
 
     if tolerance.is_some() && is_equal_to.is_none() {
-        return Err(KclError::Type(KclErrorDetails {
-            message:
+        return Err(KclError::Type(KclErrorDetails::new(
             "The `tolerance` arg is only used with `isEqualTo`. Either remove `tolerance` or add an `isEqualTo` arg."
                 .to_owned(),
-            source_ranges: vec![args.source_range],
-        }));
+            vec![args.source_range],
+        )));
     }
 
     let suffix = if let Some(err_string) = error {

rust/kcl-lib/src/std/chamfer.rs

@@ -41,10 +41,10 @@ async fn inner_chamfer(
     // If you try and tag multiple edges with a tagged chamfer, we want to return an
     // error to the user that they can only tag one edge at a time.
     if tag.is_some() && tags.len() > 1 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "You can only tag one edge at a time with a tagged chamfer. Either delete the tag for the chamfer fn if you don't need it OR separate into individual chamfer functions for each tag.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "You can only tag one edge at a time with a tagged chamfer. Either delete the tag for the chamfer fn if you don't need it OR separate into individual chamfer functions for each tag.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let mut solid = solid.clone();

rust/kcl-lib/src/std/clone.rs

@@ -84,10 +84,10 @@ async fn inner_clone(
     fix_tags_and_references(&mut new_geometry, old_id, exec_state, &args)
         .await
         .map_err(|e| {
-            KclError::Internal(KclErrorDetails {
-                message: format!("failed to fix tags and references: {:?}", e),
-                source_ranges: vec![args.source_range],
-            })
+            KclError::Internal(KclErrorDetails::new(
+                format!("failed to fix tags and references: {:?}", e),
+                vec![args.source_range],
+            ))
         })?;
 
     Ok(new_geometry)

rust/kcl-lib/src/std/csg.rs

@@ -24,10 +24,10 @@ pub async fn union(exec_state: &mut ExecState, args: Args) -> Result<KclValue, K
     let tolerance: Option<TyF64> = args.get_kw_arg_opt_typed("tolerance", &RuntimeType::length(), exec_state)?;
 
     if solids.len() < 2 {
-        return Err(KclError::UndefinedValue(KclErrorDetails {
-            message: "At least two solids are required for a union operation.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::UndefinedValue(KclErrorDetails::new(
+            "At least two solids are required for a union operation.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let solids = inner_union(solids, tolerance, exec_state, args).await?;
@@ -147,10 +147,10 @@ pub(crate) async fn inner_union(
         modeling_response: OkModelingCmdResponse::BooleanUnion(BooleanUnion { extra_solid_ids }),
     } = result
     else {
-        return Err(KclError::Internal(KclErrorDetails {
-            message: "Failed to get the result of the union operation.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Internal(KclErrorDetails::new(
+            "Failed to get the result of the union operation.".to_string(),
+            vec![args.source_range],
+        )));
     };
 
     // If we have more solids, set those as well.
@@ -169,10 +169,10 @@ pub async fn intersect(exec_state: &mut ExecState, args: Args) -> Result<KclValu
     let tolerance: Option<TyF64> = args.get_kw_arg_opt_typed("tolerance", &RuntimeType::length(), exec_state)?;
 
     if solids.len() < 2 {
-        return Err(KclError::UndefinedValue(KclErrorDetails {
-            message: "At least two solids are required for an intersect operation.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::UndefinedValue(KclErrorDetails::new(
+            "At least two solids are required for an intersect operation.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let solids = inner_intersect(solids, tolerance, exec_state, args).await?;
@@ -273,10 +273,10 @@ pub(crate) async fn inner_intersect(
         modeling_response: OkModelingCmdResponse::BooleanIntersection(BooleanIntersection { extra_solid_ids }),
     } = result
     else {
-        return Err(KclError::Internal(KclErrorDetails {
-            message: "Failed to get the result of the intersection operation.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Internal(KclErrorDetails::new(
+            "Failed to get the result of the intersection operation.".to_string(),
+            vec![args.source_range],
+        )));
     };
 
     // If we have more solids, set those as well.
@@ -397,10 +397,10 @@ pub(crate) async fn inner_subtract(
         modeling_response: OkModelingCmdResponse::BooleanSubtract(BooleanSubtract { extra_solid_ids }),
     } = result
     else {
-        return Err(KclError::Internal(KclErrorDetails {
-            message: "Failed to get the result of the subtract operation.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Internal(KclErrorDetails::new(
+            "Failed to get the result of the subtract operation.".to_string(),
+            vec![args.source_range],
+        )));
     };
 
     // If we have more solids, set those as well.

rust/kcl-lib/src/std/edge.rs

@@ -87,10 +87,10 @@ async fn inner_get_opposite_edge(
         modeling_response: OkModelingCmdResponse::Solid3dGetOppositeEdge(opposite_edge),
     } = &resp
     else {
-        return Err(KclError::Engine(KclErrorDetails {
-            message: format!("mcmd::Solid3dGetOppositeEdge response was not as expected: {:?}", resp),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Engine(KclErrorDetails::new(
+            format!("mcmd::Solid3dGetOppositeEdge response was not as expected: {:?}", resp),
+            vec![args.source_range],
+        )));
     };
 
     Ok(opposite_edge.edge)
@@ -172,20 +172,20 @@ async fn inner_get_next_adjacent_edge(
         modeling_response: OkModelingCmdResponse::Solid3dGetNextAdjacentEdge(adjacent_edge),
     } = &resp
     else {
-        return Err(KclError::Engine(KclErrorDetails {
-            message: format!(
+        return Err(KclError::Engine(KclErrorDetails::new(
+            format!(
                 "mcmd::Solid3dGetNextAdjacentEdge response was not as expected: {:?}",
                 resp
             ),
-            source_ranges: vec![args.source_range],
-        }));
+            vec![args.source_range],
+        )));
     };
 
     adjacent_edge.edge.ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("No edge found next adjacent to tag: `{}`", edge.value),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("No edge found next adjacent to tag: `{}`", edge.value),
+            vec![args.source_range],
+        ))
     })
 }
 
@@ -264,20 +264,20 @@ async fn inner_get_previous_adjacent_edge(
         modeling_response: OkModelingCmdResponse::Solid3dGetPrevAdjacentEdge(adjacent_edge),
     } = &resp
     else {
-        return Err(KclError::Engine(KclErrorDetails {
-            message: format!(
+        return Err(KclError::Engine(KclErrorDetails::new(
+            format!(
                 "mcmd::Solid3dGetPrevAdjacentEdge response was not as expected: {:?}",
                 resp
             ),
-            source_ranges: vec![args.source_range],
-        }));
+            vec![args.source_range],
+        )));
     };
 
     adjacent_edge.edge.ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("No edge found previous adjacent to tag: `{}`", edge.value),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("No edge found previous adjacent to tag: `{}`", edge.value),
+            vec![args.source_range],
+        ))
     })
 }
 
@@ -336,10 +336,10 @@ async fn inner_get_common_edge(
     }
 
     if faces.len() != 2 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "getCommonEdge requires exactly two tags for faces".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "getCommonEdge requires exactly two tags for faces".to_string(),
+            vec![args.source_range],
+        )));
     }
     let first_face_id = args.get_adjacent_face_to_tag(exec_state, &faces[0], false).await?;
     let second_face_id = args.get_adjacent_face_to_tag(exec_state, &faces[1], false).await?;
@@ -348,10 +348,10 @@ async fn inner_get_common_edge(
     let second_tagged_path = args.get_tag_engine_info(exec_state, &faces[1])?;
 
     if first_tagged_path.sketch != second_tagged_path.sketch {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "getCommonEdge requires the faces to be in the same original sketch".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "getCommonEdge requires the faces to be in the same original sketch".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     // Flush the batch for our fillets/chamfers if there are any.
@@ -377,19 +377,19 @@ async fn inner_get_common_edge(
         modeling_response: OkModelingCmdResponse::Solid3dGetCommonEdge(common_edge),
     } = &resp
     else {
-        return Err(KclError::Engine(KclErrorDetails {
-            message: format!("mcmd::Solid3dGetCommonEdge response was not as expected: {:?}", resp),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Engine(KclErrorDetails::new(
+            format!("mcmd::Solid3dGetCommonEdge response was not as expected: {:?}", resp),
+            vec![args.source_range],
+        )));
     };
 
     common_edge.edge.ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!(
+        KclError::Type(KclErrorDetails::new(
+            format!(
                 "No common edge was found between `{}` and `{}`",
                 faces[0].value, faces[1].value
             ),
-            source_ranges: vec![args.source_range],
-        })
+            vec![args.source_range],
+        ))
     })
 }

rust/kcl-lib/src/std/extrude.rs

@@ -175,11 +175,11 @@ async fn inner_extrude(
     let mut solids = Vec::new();
 
     if symmetric.unwrap_or(false) && bidirectional_length.is_some() {
-        return Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message: "You cannot give both `symmetric` and `bidirectional` params, you have to choose one or the other"
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            "You cannot give both `symmetric` and `bidirectional` params, you have to choose one or the other"
                 .to_owned(),
-        }));
+            vec![args.source_range],
+        )));
     }
 
     let bidirection = bidirectional_length.map(|l| LengthUnit(l.to_mm()));
@@ -262,10 +262,10 @@ pub(crate) async fn do_post_extrude<'a>(
         // The "get extrusion face info" API call requires *any* edge on the sketch being extruded.
         // So, let's just use the first one.
         let Some(any_edge_id) = sketch.paths.first().map(|edge| edge.get_base().geo_meta.id) else {
-            return Err(KclError::Type(KclErrorDetails {
-                message: "Expected a non-empty sketch".to_string(),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Type(KclErrorDetails::new(
+                "Expected a non-empty sketch".to_owned(),
+                vec![args.source_range],
+            )));
         };
         any_edge_id
     };
@@ -387,13 +387,13 @@ pub(crate) async fn do_post_extrude<'a>(
     // Add the tags for the start or end caps.
     if let Some(tag_start) = named_cap_tags.start {
         let Some(start_cap_id) = start_cap_id else {
-            return Err(KclError::Type(KclErrorDetails {
-                message: format!(
+            return Err(KclError::Type(KclErrorDetails::new(
+                format!(
                     "Expected a start cap ID for tag `{}` for extrusion of sketch {:?}",
                     tag_start.name, sketch.id
                 ),
-                source_ranges: vec![args.source_range],
-            }));
+                vec![args.source_range],
+            )));
         };
 
         new_value.push(ExtrudeSurface::ExtrudePlane(crate::execution::ExtrudePlane {
@@ -407,13 +407,13 @@ pub(crate) async fn do_post_extrude<'a>(
     }
     if let Some(tag_end) = named_cap_tags.end {
         let Some(end_cap_id) = end_cap_id else {
-            return Err(KclError::Type(KclErrorDetails {
-                message: format!(
+            return Err(KclError::Type(KclErrorDetails::new(
+                format!(
                     "Expected an end cap ID for tag `{}` for extrusion of sketch {:?}",
                     tag_end.name, sketch.id
                 ),
-                source_ranges: vec![args.source_range],
-            }));
+                vec![args.source_range],
+            )));
         };
 
         new_value.push(ExtrudeSurface::ExtrudePlane(crate::execution::ExtrudePlane {

rust/kcl-lib/src/std/fillet.rs

@@ -49,10 +49,11 @@ pub(super) fn validate_unique<T: Eq + std::hash::Hash>(tags: &[(T, SourceRange)]
         }
     }
     if !duplicate_tags_source.is_empty() {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "The same edge ID is being referenced multiple times, which is not allowed. Please select a different edge".to_string(),
-            source_ranges: duplicate_tags_source,
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "The same edge ID is being referenced multiple times, which is not allowed. Please select a different edge"
+                .to_string(),
+            duplicate_tags_source,
+        )));
     }
     Ok(())
 }

rust/kcl-lib/src/std/helix.rs

@@ -6,7 +6,7 @@ use kittycad_modeling_cmds::{self as kcmc, shared::Point3d};
 
 use super::args::TyF64;
 use crate::{
-    errors::KclError,
+    errors::{KclError, KclErrorDetails},
     execution::{
         types::{PrimitiveType, RuntimeType},
         ExecState, Helix as HelixValue, KclValue, Solid,
@@ -33,50 +33,50 @@ pub async fn helix(exec_state: &mut ExecState, args: Args) -> Result<KclValue, K
 
     // Make sure we have a radius if we don't have a cylinder.
     if radius.is_none() && cylinder.is_none() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
-            message: "Radius is required when creating a helix without a cylinder.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
+            "Radius is required when creating a helix without a cylinder.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     // Make sure we don't have a radius if we have a cylinder.
     if radius.is_some() && cylinder.is_some() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
-            message: "Radius is not allowed when creating a helix with a cylinder.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
+            "Radius is not allowed when creating a helix with a cylinder.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     // Make sure we have an axis if we don't have a cylinder.
     if axis.is_none() && cylinder.is_none() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
-            message: "Axis is required when creating a helix without a cylinder.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
+            "Axis is required when creating a helix without a cylinder.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     // Make sure we don't have an axis if we have a cylinder.
     if axis.is_some() && cylinder.is_some() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
-            message: "Axis is not allowed when creating a helix with a cylinder.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
+            "Axis is not allowed when creating a helix with a cylinder.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     // Make sure we have a radius if we have an axis.
     if radius.is_none() && axis.is_some() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
-            message: "Radius is required when creating a helix around an axis.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
+            "Radius is required when creating a helix around an axis.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     // Make sure we have an axis if we have a radius.
     if axis.is_none() && radius.is_some() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
-            message: "Axis is required when creating a helix around an axis.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
+            "Axis is required when creating a helix around an axis.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let value = inner_helix(
@@ -140,10 +140,10 @@ async fn inner_helix(
             Axis3dOrEdgeReference::Axis { direction, origin } => {
                 // Make sure they gave us a length.
                 let Some(length) = length else {
-                    return Err(KclError::Semantic(crate::errors::KclErrorDetails {
-                        message: "Length is required when creating a helix around an axis.".to_string(),
-                        source_ranges: vec![args.source_range],
-                    }));
+                    return Err(KclError::Semantic(KclErrorDetails::new(
+                        "Length is required when creating a helix around an axis.".to_owned(),
+                        vec![args.source_range],
+                    )));
                 };
 
                 args.batch_modeling_cmd(

rust/kcl-lib/src/std/loft.rs

@@ -148,13 +148,13 @@ async fn inner_loft(
 ) -> Result<Box<Solid>, KclError> {
     // Make sure we have at least two sketches.
     if sketches.len() < 2 {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message: format!(
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            format!(
                 "Loft requires at least two sketches, but only {} were provided.",
                 sketches.len()
             ),
-            source_ranges: vec![args.source_range],
-        }));
+            vec![args.source_range],
+        )));
     }
 
     let id = exec_state.next_uuid();

rust/kcl-lib/src/std/math.rs

@@ -56,13 +56,13 @@ pub async fn sqrt(exec_state: &mut ExecState, args: Args) -> Result<KclValue, Kc
     let input: TyF64 = args.get_unlabeled_kw_arg_typed("input", &RuntimeType::num_any(), exec_state)?;
 
     if input.n < 0.0 {
-        return Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message: format!(
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            format!(
                 "Attempt to take square root (`sqrt`) of a number less than zero ({})",
                 input.n
             ),
-        }));
+            vec![args.source_range],
+        )));
     }
 
     let result = input.n.sqrt();

rust/kcl-lib/src/std/mirror.rs

@@ -101,10 +101,10 @@ async fn inner_mirror_2d(
                 OkModelingCmdResponse::EntityGetAllChildUuids(EntityGetAllChildUuids { entity_ids: child_ids }),
         } = response
         else {
-            return Err(KclError::Internal(KclErrorDetails {
-                message: "Expected a successful response from EntityGetAllChildUuids".to_string(),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Internal(KclErrorDetails::new(
+                "Expected a successful response from EntityGetAllChildUuids".to_string(),
+                vec![args.source_range],
+            )));
         };
 
         if child_ids.len() >= 2 {
@@ -112,10 +112,10 @@ async fn inner_mirror_2d(
             let child_id = child_ids[1];
             sketch.mirror = Some(child_id);
         } else {
-            return Err(KclError::Type(KclErrorDetails {
-                message: "Expected child uuids to be >= 2".to_string(),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Type(KclErrorDetails::new(
+                "Expected child uuids to be >= 2".to_string(),
+                vec![args.source_range],
+            )));
         }
     }
 

rust/kcl-lib/src/std/patterns.rs

@@ -264,10 +264,10 @@ async fn inner_pattern_transform<'a>(
     // Build the vec of transforms, one for each repetition.
     let mut transform_vec = Vec::with_capacity(usize::try_from(instances).unwrap());
     if instances < 1 {
-        return Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message: MUST_HAVE_ONE_INSTANCE.to_owned(),
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            MUST_HAVE_ONE_INSTANCE.to_owned(),
+            vec![args.source_range],
+        )));
     }
     for i in 1..instances {
         let t = make_transform::<Solid>(i, transform, args.source_range, exec_state, &args.ctx).await?;
@@ -318,10 +318,10 @@ async fn inner_pattern_transform_2d<'a>(
     // Build the vec of transforms, one for each repetition.
     let mut transform_vec = Vec::with_capacity(usize::try_from(instances).unwrap());
     if instances < 1 {
-        return Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message: MUST_HAVE_ONE_INSTANCE.to_owned(),
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            MUST_HAVE_ONE_INSTANCE.to_owned(),
+            vec![args.source_range],
+        )));
     }
     for i in 1..instances {
         let t = make_transform::<Sketch>(i, transform, args.source_range, exec_state, &args.ctx).await?;
@@ -398,10 +398,10 @@ async fn send_pattern_transform<T: GeometryTrait>(
         }
         &mock_ids
     } else {
-        return Err(KclError::Engine(KclErrorDetails {
-            message: format!("EntityLinearPattern response was not as expected: {:?}", resp),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Engine(KclErrorDetails::new(
+            format!("EntityLinearPattern response was not as expected: {:?}", resp),
+            vec![args.source_range],
+        )));
     };
 
     let mut geometries = vec![solid.clone()];
@@ -444,10 +444,10 @@ async fn make_transform<T: GeometryTrait>(
     // Unpack the returned transform object.
     let source_ranges = vec![source_range];
     let transform_fn_return = transform_fn_return.ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
-            message: "Transform function must return a value".to_string(),
-            source_ranges: source_ranges.clone(),
-        })
+        KclError::Semantic(KclErrorDetails::new(
+            "Transform function must return a value".to_string(),
+            source_ranges.clone(),
+        ))
     })?;
     let transforms = match transform_fn_return {
         KclValue::Object { value, meta: _ } => vec![value],
@@ -455,19 +455,19 @@ async fn make_transform<T: GeometryTrait>(
             let transforms: Vec<_> = value
                 .into_iter()
                 .map(|val| {
-                    val.into_object().ok_or(KclError::Semantic(KclErrorDetails {
-                        message: "Transform function must return a transform object".to_string(),
-                        source_ranges: source_ranges.clone(),
-                    }))
+                    val.into_object().ok_or(KclError::Semantic(KclErrorDetails::new(
+                        "Transform function must return a transform object".to_string(),
+                        source_ranges.clone(),
+                    )))
                 })
                 .collect::<Result<_, _>>()?;
             transforms
         }
         _ => {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "Transform function must return a transform object".to_string(),
-                source_ranges: source_ranges.clone(),
-            }))
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "Transform function must return a transform object".to_string(),
+                source_ranges.clone(),
+            )))
         }
     };
 
@@ -487,10 +487,10 @@ fn transform_from_obj_fields<T: GeometryTrait>(
         Some(KclValue::Bool { value: true, .. }) => true,
         Some(KclValue::Bool { value: false, .. }) => false,
         Some(_) => {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "The 'replicate' key must be a bool".to_string(),
-                source_ranges: source_ranges.clone(),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "The 'replicate' key must be a bool".to_string(),
+                source_ranges.clone(),
+            )));
         }
         None => true,
     };
@@ -519,11 +519,10 @@ fn transform_from_obj_fields<T: GeometryTrait>(
     let mut rotation = Rotation::default();
     if let Some(rot) = transform.get("rotation") {
         let KclValue::Object { value: rot, meta: _ } = rot else {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "The 'rotation' key must be an object (with optional fields 'angle', 'axis' and 'origin')"
-                    .to_string(),
-                source_ranges: source_ranges.clone(),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "The 'rotation' key must be an object (with optional fields 'angle', 'axis' and 'origin')".to_owned(),
+                source_ranges.clone(),
+            )));
         };
         if let Some(axis) = rot.get("axis") {
             rotation.axis = point_3d_to_mm(T::array_to_point3d(axis, source_ranges.clone(), exec_state)?).into();
@@ -534,10 +533,10 @@ fn transform_from_obj_fields<T: GeometryTrait>(
                     rotation.angle = Angle::from_degrees(*number);
                 }
                 _ => {
-                    return Err(KclError::Semantic(KclErrorDetails {
-                        message: "The 'rotation.angle' key must be a number (of degrees)".to_string(),
-                        source_ranges: source_ranges.clone(),
-                    }));
+                    return Err(KclError::Semantic(KclErrorDetails::new(
+                        "The 'rotation.angle' key must be a number (of degrees)".to_owned(),
+                        source_ranges.clone(),
+                    )));
                 }
             }
         }
@@ -568,15 +567,15 @@ fn array_to_point3d(
 ) -> Result<[TyF64; 3], KclError> {
     val.coerce(&RuntimeType::point3d(), exec_state)
         .map_err(|e| {
-            KclError::Semantic(KclErrorDetails {
-                message: format!(
+            KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "Expected an array of 3 numbers (i.e., a 3D point), found {}",
                     e.found
                         .map(|t| t.human_friendly_type())
                         .unwrap_or_else(|| val.human_friendly_type().to_owned())
                 ),
                 source_ranges,
-            })
+            ))
         })
         .map(|val| val.as_point3d().unwrap())
 }
@@ -588,15 +587,15 @@ fn array_to_point2d(
 ) -> Result<[TyF64; 2], KclError> {
     val.coerce(&RuntimeType::point2d(), exec_state)
         .map_err(|e| {
-            KclError::Semantic(KclErrorDetails {
-                message: format!(
+            KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "Expected an array of 2 numbers (i.e., a 2D point), found {}",
                     e.found
                         .map(|t| t.human_friendly_type())
                         .unwrap_or_else(|| val.human_friendly_type().to_owned())
                 ),
                 source_ranges,
-            })
+            ))
         })
         .map(|val| val.as_point2d().unwrap())
 }
@@ -757,12 +756,11 @@ pub async fn pattern_linear_2d(exec_state: &mut ExecState, args: Args) -> Result
 
     let axis = axis.to_point2d();
     if axis[0].n == 0.0 && axis[1].n == 0.0 {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message:
+        return Err(KclError::Semantic(KclErrorDetails::new(
             "The axis of the linear pattern cannot be the zero vector. Otherwise they will just duplicate in place."
-                    .to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+                .to_owned(),
+            vec![args.source_range],
+        )));
     }
 
     let sketches = inner_pattern_linear_2d(sketches, instances, distance, axis, use_original, exec_state, args).await?;
@@ -860,12 +858,11 @@ pub async fn pattern_linear_3d(exec_state: &mut ExecState, args: Args) -> Result
 
     let axis = axis.to_point3d();
     if axis[0].n == 0.0 && axis[1].n == 0.0 && axis[2].n == 0.0 {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message:
+        return Err(KclError::Semantic(KclErrorDetails::new(
             "The axis of the linear pattern cannot be the zero vector. Otherwise they will just duplicate in place."
-                    .to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+                .to_owned(),
+            vec![args.source_range],
+        )));
     }
 
     let solids = inner_pattern_linear_3d(solids, instances, distance, axis, use_original, exec_state, args).await?;
@@ -1210,10 +1207,10 @@ async fn inner_pattern_circular_2d(
         .await?;
 
         let Geometries::Sketches(new_sketches) = geometries else {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "Expected a vec of sketches".to_string(),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "Expected a vec of sketches".to_string(),
+                vec![args.source_range],
+            )));
         };
 
         sketches.extend(new_sketches);
@@ -1333,10 +1330,10 @@ async fn inner_pattern_circular_3d(
         .await?;
 
         let Geometries::Solids(new_solids) = geometries else {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "Expected a vec of solids".to_string(),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "Expected a vec of solids".to_string(),
+                vec![args.source_range],
+            )));
         };
 
         solids.extend(new_solids);
@@ -1358,10 +1355,10 @@ async fn pattern_circular(
             return Ok(Geometries::from(geometry));
         }
         RepetitionsNeeded::Invalid => {
-            return Err(KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![args.source_range],
-                message: MUST_HAVE_ONE_INSTANCE.to_owned(),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                MUST_HAVE_ONE_INSTANCE.to_owned(),
+                vec![args.source_range],
+            )));
         }
     };
 
@@ -1403,10 +1400,10 @@ async fn pattern_circular(
         }
         &mock_ids
     } else {
-        return Err(KclError::Engine(KclErrorDetails {
-            message: format!("EntityCircularPattern response was not as expected: {:?}", resp),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Engine(KclErrorDetails::new(
+            format!("EntityCircularPattern response was not as expected: {:?}", resp),
+            vec![args.source_range],
+        )));
     };
 
     let geometries = match geometry {

rust/kcl-lib/src/std/revolve.rs

@@ -75,10 +75,10 @@ async fn inner_revolve(
         // We don't use validate() here because we want to return a specific error message that is
         // nice and we use the other data in the docs, so we still need use the derive above for the json schema.
         if !(-360.0..=360.0).contains(&angle) || angle == 0.0 {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Expected angle to be between -360 and 360 and not 0, found `{}`", angle),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Expected angle to be between -360 and 360 and not 0, found `{}`", angle),
+                vec![args.source_range],
+            )));
         }
     }
 
@@ -87,35 +87,35 @@ async fn inner_revolve(
         // We don't use validate() here because we want to return a specific error message that is
         // nice and we use the other data in the docs, so we still need use the derive above for the json schema.
         if !(-360.0..=360.0).contains(&bidirectional_angle) || bidirectional_angle == 0.0 {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!(
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!(
                     "Expected bidirectional angle to be between -360 and 360 and not 0, found `{}`",
                     bidirectional_angle
                 ),
-                source_ranges: vec![args.source_range],
-            }));
+                vec![args.source_range],
+            )));
         }
 
         if let Some(angle) = angle {
             let ang = angle.signum() * bidirectional_angle + angle;
             if !(-360.0..=360.0).contains(&ang) {
-                return Err(KclError::Semantic(KclErrorDetails {
-                    message: format!(
+                return Err(KclError::Semantic(KclErrorDetails::new(
+                    format!(
                         "Combined angle and bidirectional must be between -360 and 360, found '{}'",
                         ang
                     ),
-                    source_ranges: vec![args.source_range],
-                }));
+                    vec![args.source_range],
+                )));
             }
         }
     }
 
     if symmetric.unwrap_or(false) && bidirectional_angle.is_some() {
-        return Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message: "You cannot give both `symmetric` and `bidirectional` params, you have to choose one or the other"
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            "You cannot give both `symmetric` and `bidirectional` params, you have to choose one or the other"
                 .to_owned(),
-        }));
+            vec![args.source_range],
+        )));
     }
 
     let angle = Angle::from_degrees(angle.unwrap_or(360.0));

rust/kcl-lib/src/std/segment.rs

@@ -59,10 +59,10 @@ pub async fn segment_end(exec_state: &mut ExecState, args: Args) -> Result<KclVa
 fn inner_segment_end(tag: &TagIdentifier, exec_state: &mut ExecState, args: Args) -> Result<[TyF64; 2], KclError> {
     let line = args.get_tag_engine_info(exec_state, tag)?;
     let path = line.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected a line segment with a path, found `{:?}`", line),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected a line segment with a path, found `{:?}`", line),
+            vec![args.source_range],
+        ))
     })?;
     let (p, ty) = path.end_point_components();
     // Docs generation isn't smart enough to handle ([f64; 2], NumericType).
@@ -104,10 +104,10 @@ pub async fn segment_end_x(exec_state: &mut ExecState, args: Args) -> Result<Kcl
 fn inner_segment_end_x(tag: &TagIdentifier, exec_state: &mut ExecState, args: Args) -> Result<TyF64, KclError> {
     let line = args.get_tag_engine_info(exec_state, tag)?;
     let path = line.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected a line segment with a path, found `{:?}`", line),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected a line segment with a path, found `{:?}`", line),
+            vec![args.source_range],
+        ))
     })?;
 
     Ok(TyF64::new(path.get_base().to[0], path.get_base().units.into()))
@@ -147,10 +147,10 @@ pub async fn segment_end_y(exec_state: &mut ExecState, args: Args) -> Result<Kcl
 fn inner_segment_end_y(tag: &TagIdentifier, exec_state: &mut ExecState, args: Args) -> Result<TyF64, KclError> {
     let line = args.get_tag_engine_info(exec_state, tag)?;
     let path = line.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected a line segment with a path, found `{:?}`", line),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected a line segment with a path, found `{:?}`", line),
+            vec![args.source_range],
+        ))
     })?;
 
     Ok(path.get_to()[1].clone())
@@ -201,10 +201,10 @@ pub async fn segment_start(exec_state: &mut ExecState, args: Args) -> Result<Kcl
 fn inner_segment_start(tag: &TagIdentifier, exec_state: &mut ExecState, args: Args) -> Result<[TyF64; 2], KclError> {
     let line = args.get_tag_engine_info(exec_state, tag)?;
     let path = line.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected a line segment with a path, found `{:?}`", line),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected a line segment with a path, found `{:?}`", line),
+            vec![args.source_range],
+        ))
     })?;
     let (p, ty) = path.start_point_components();
     // Docs generation isn't smart enough to handle ([f64; 2], NumericType).
@@ -246,10 +246,10 @@ pub async fn segment_start_x(exec_state: &mut ExecState, args: Args) -> Result<K
 fn inner_segment_start_x(tag: &TagIdentifier, exec_state: &mut ExecState, args: Args) -> Result<TyF64, KclError> {
     let line = args.get_tag_engine_info(exec_state, tag)?;
     let path = line.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected a line segment with a path, found `{:?}`", line),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected a line segment with a path, found `{:?}`", line),
+            vec![args.source_range],
+        ))
     })?;
 
     Ok(path.get_from()[0].clone())
@@ -289,10 +289,10 @@ pub async fn segment_start_y(exec_state: &mut ExecState, args: Args) -> Result<K
 fn inner_segment_start_y(tag: &TagIdentifier, exec_state: &mut ExecState, args: Args) -> Result<TyF64, KclError> {
     let line = args.get_tag_engine_info(exec_state, tag)?;
     let path = line.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected a line segment with a path, found `{:?}`", line),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected a line segment with a path, found `{:?}`", line),
+            vec![args.source_range],
+        ))
     })?;
 
     Ok(path.get_from()[1].clone())
@@ -334,10 +334,10 @@ fn inner_last_segment_x(sketch: Sketch, args: Args) -> Result<TyF64, KclError> {
         .paths
         .last()
         .ok_or_else(|| {
-            KclError::Type(KclErrorDetails {
-                message: format!("Expected a Sketch with at least one segment, found `{:?}`", sketch),
-                source_ranges: vec![args.source_range],
-            })
+            KclError::Type(KclErrorDetails::new(
+                format!("Expected a Sketch with at least one segment, found `{:?}`", sketch),
+                vec![args.source_range],
+            ))
         })?
         .get_base();
 
@@ -381,10 +381,10 @@ fn inner_last_segment_y(sketch: Sketch, args: Args) -> Result<TyF64, KclError> {
         .paths
         .last()
         .ok_or_else(|| {
-            KclError::Type(KclErrorDetails {
-                message: format!("Expected a Sketch with at least one segment, found `{:?}`", sketch),
-                source_ranges: vec![args.source_range],
-            })
+            KclError::Type(KclErrorDetails::new(
+                format!("Expected a Sketch with at least one segment, found `{:?}`", sketch),
+                vec![args.source_range],
+            ))
         })?
         .get_base();
 
@@ -429,10 +429,10 @@ pub async fn segment_length(exec_state: &mut ExecState, args: Args) -> Result<Kc
 fn inner_segment_length(tag: &TagIdentifier, exec_state: &mut ExecState, args: Args) -> Result<TyF64, KclError> {
     let line = args.get_tag_engine_info(exec_state, tag)?;
     let path = line.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected a line segment with a path, found `{:?}`", line),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected a line segment with a path, found `{:?}`", line),
+            vec![args.source_range],
+        ))
     })?;
 
     Ok(path.length())
@@ -473,10 +473,10 @@ pub async fn segment_angle(exec_state: &mut ExecState, args: Args) -> Result<Kcl
 fn inner_segment_angle(tag: &TagIdentifier, exec_state: &mut ExecState, args: Args) -> Result<f64, KclError> {
     let line = args.get_tag_engine_info(exec_state, tag)?;
     let path = line.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected a line segment with a path, found `{:?}`", line),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected a line segment with a path, found `{:?}`", line),
+            vec![args.source_range],
+        ))
     })?;
 
     let result = between(path.get_base().from, path.get_base().to);
@@ -575,10 +575,10 @@ pub async fn tangent_to_end(exec_state: &mut ExecState, args: Args) -> Result<Kc
 async fn inner_tangent_to_end(tag: &TagIdentifier, exec_state: &mut ExecState, args: Args) -> Result<f64, KclError> {
     let line = args.get_tag_engine_info(exec_state, tag)?;
     let path = line.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected a line segment with a path, found `{:?}`", line),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected a line segment with a path, found `{:?}`", line),
+            vec![args.source_range],
+        ))
     })?;
 
     let from = untype_point(path.get_to()).0;

rust/kcl-lib/src/std/shapes.rs

@@ -325,17 +325,17 @@ async fn inner_polygon(
     args: Args,
 ) -> Result<Sketch, KclError> {
     if num_sides < 3 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Polygon must have at least 3 sides".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Polygon must have at least 3 sides".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     if radius.n <= 0.0 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Radius must be greater than 0".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Radius must be greater than 0".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let (sketch_surface, units) = match sketch_surface_or_group {

rust/kcl-lib/src/std/shell.rs

@@ -36,17 +36,17 @@ async fn inner_shell(
     args: Args,
 ) -> Result<Vec<Solid>, KclError> {
     if faces.is_empty() {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "You must shell at least one face".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "You must shell at least one face".to_owned(),
+            vec![args.source_range],
+        )));
     }
 
     if solids.is_empty() {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "You must shell at least one solid".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "You must shell at least one solid".to_owned(),
+            vec![args.source_range],
+        )));
     }
 
     let mut face_ids = Vec::new();
@@ -63,20 +63,19 @@ async fn inner_shell(
     }
 
     if face_ids.is_empty() {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Expected at least one valid face".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Expected at least one valid face".to_owned(),
+            vec![args.source_range],
+        )));
     }
 
     // Make sure all the solids have the same id, as we are going to shell them all at
     // once.
     if !solids.iter().all(|eg| eg.id == solids[0].id) {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "All solids stem from the same root object, like multiple sketch on face extrusions, etc."
-                .to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "All solids stem from the same root object, like multiple sketch on face extrusions, etc.".to_owned(),
+            vec![args.source_range],
+        )));
     }
 
     args.batch_modeling_cmd(

rust/kcl-lib/src/std/sketch.rs

@@ -64,16 +64,16 @@ impl FaceTag {
         match self {
             FaceTag::Tag(ref t) => args.get_adjacent_face_to_tag(exec_state, t, must_be_planar).await,
             FaceTag::StartOrEnd(StartOrEnd::Start) => solid.start_cap_id.ok_or_else(|| {
-                KclError::Type(KclErrorDetails {
-                    message: "Expected a start face".to_string(),
-                    source_ranges: vec![args.source_range],
-                })
+                KclError::Type(KclErrorDetails::new(
+                    "Expected a start face".to_string(),
+                    vec![args.source_range],
+                ))
             }),
             FaceTag::StartOrEnd(StartOrEnd::End) => solid.end_cap_id.ok_or_else(|| {
-                KclError::Type(KclErrorDetails {
-                    message: "Expected an end face".to_string(),
-                    source_ranges: vec![args.source_range],
-                })
+                KclError::Type(KclErrorDetails::new(
+                    "Expected an end face".to_string(),
+                    vec![args.source_range],
+                ))
             }),
         }
     }
@@ -329,19 +329,18 @@ async fn straight_line(
     let from = sketch.current_pen_position()?;
     let (point, is_absolute) = match (end_absolute, end) {
         (Some(_), Some(_)) => {
-            return Err(KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![args.source_range],
-                message: "You cannot give both `end` and `endAbsolute` params, you have to choose one or the other"
-                    .to_owned(),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "You cannot give both `end` and `endAbsolute` params, you have to choose one or the other".to_owned(),
+                vec![args.source_range],
+            )));
         }
         (Some(end_absolute), None) => (end_absolute, true),
         (None, Some(end)) => (end, false),
         (None, None) => {
-            return Err(KclError::Semantic(KclErrorDetails {
-                source_ranges: vec![args.source_range],
-                message: format!("You must supply either `{relative_name}` or `endAbsolute` arguments"),
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("You must supply either `{relative_name}` or `endAbsolute` arguments"),
+                vec![args.source_range],
+            )));
         }
     };
 
@@ -608,10 +607,10 @@ async fn inner_angled_line(
         .filter(|x| x.is_some())
         .count();
     if options_given > 1 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: " one of `length`, `lengthX`, `lengthY`, `endAbsoluteX`, `endAbsoluteY` can be given".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            " one of `length`, `lengthX`, `lengthY`, `endAbsoluteX`, `endAbsoluteY` can be given".to_string(),
+            vec![args.source_range],
+        )));
     }
     if let Some(length_x) = length_x {
         return inner_angled_line_of_x_length(angle, length_x, sketch, tag, exec_state, args).await;
@@ -636,15 +635,14 @@ async fn inner_angled_line(
         (None, None, None, None, Some(end_absolute_y)) => {
             inner_angled_line_to_y(angle_degrees, end_absolute_y, sketch, tag, exec_state, args).await
         }
-        (None, None, None, None, None) => Err(KclError::Type(KclErrorDetails {
-            message: "One of `length`, `lengthX`, `lengthY`, `endAbsoluteX`, `endAbsoluteY` must be given".to_string(),
-            source_ranges: vec![args.source_range],
-        })),
-        _ => Err(KclError::Type(KclErrorDetails {
-            message: "Only One of `length`, `lengthX`, `lengthY`, `endAbsoluteX`, `endAbsoluteY` can be given"
-                .to_string(),
-            source_ranges: vec![args.source_range],
-        })),
+        (None, None, None, None, None) => Err(KclError::Type(KclErrorDetails::new(
+            "One of `length`, `lengthX`, `lengthY`, `endAbsoluteX`, `endAbsoluteY` must be given".to_string(),
+            vec![args.source_range],
+        ))),
+        _ => Err(KclError::Type(KclErrorDetails::new(
+            "Only One of `length`, `lengthX`, `lengthY`, `endAbsoluteX`, `endAbsoluteY` can be given".to_owned(),
+            vec![args.source_range],
+        ))),
     }
 }
 
@@ -715,17 +713,17 @@ async fn inner_angled_line_of_x_length(
     args: Args,
 ) -> Result<Sketch, KclError> {
     if angle_degrees.abs() == 270.0 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Cannot have an x constrained angle of 270 degrees".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Cannot have an x constrained angle of 270 degrees".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     if angle_degrees.abs() == 90.0 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Cannot have an x constrained angle of 90 degrees".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Cannot have an x constrained angle of 90 degrees".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let to = get_y_component(Angle::from_degrees(angle_degrees), length.n);
@@ -747,17 +745,17 @@ async fn inner_angled_line_to_x(
     let from = sketch.current_pen_position()?;
 
     if angle_degrees.abs() == 270.0 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Cannot have an x constrained angle of 270 degrees".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Cannot have an x constrained angle of 270 degrees".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     if angle_degrees.abs() == 90.0 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Cannot have an x constrained angle of 90 degrees".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Cannot have an x constrained angle of 90 degrees".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let x_component = x_to.to_length_units(from.units) - from.x;
@@ -782,17 +780,17 @@ async fn inner_angled_line_of_y_length(
     args: Args,
 ) -> Result<Sketch, KclError> {
     if angle_degrees.abs() == 0.0 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Cannot have a y constrained angle of 0 degrees".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Cannot have a y constrained angle of 0 degrees".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     if angle_degrees.abs() == 180.0 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Cannot have a y constrained angle of 180 degrees".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Cannot have a y constrained angle of 180 degrees".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let to = get_x_component(Angle::from_degrees(angle_degrees), length.n);
@@ -814,17 +812,17 @@ async fn inner_angled_line_to_y(
     let from = sketch.current_pen_position()?;
 
     if angle_degrees.abs() == 0.0 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Cannot have a y constrained angle of 0 degrees".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Cannot have a y constrained angle of 0 degrees".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     if angle_degrees.abs() == 180.0 {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Cannot have a y constrained angle of 180 degrees".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Cannot have a y constrained angle of 180 degrees".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let y_component = y_to.to_length_units(from.units) - from.y;
@@ -898,10 +896,10 @@ pub async fn inner_angled_line_that_intersects(
 ) -> Result<Sketch, KclError> {
     let intersect_path = args.get_tag_engine_info(exec_state, &intersect_tag)?;
     let path = intersect_path.path.clone().ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
-            message: format!("Expected an intersect path with a path, found `{:?}`", intersect_path),
-            source_ranges: vec![args.source_range],
-        })
+        KclError::Type(KclErrorDetails::new(
+            format!("Expected an intersect path with a path, found `{:?}`", intersect_path),
+            vec![args.source_range],
+        ))
     })?;
 
     let from = sketch.current_pen_position()?;
@@ -1176,10 +1174,10 @@ async fn inner_start_sketch_on(
         SketchData::Plane(plane) => {
             if plane.value == crate::exec::PlaneType::Uninit {
                 if plane.info.origin.units == UnitLen::Unknown {
-                    return Err(KclError::Semantic(KclErrorDetails {
-                        message: "Origin of plane has unknown units".to_string(),
-                        source_ranges: vec![args.source_range],
-                    }));
+                    return Err(KclError::Semantic(KclErrorDetails::new(
+                        "Origin of plane has unknown units".to_string(),
+                        vec![args.source_range],
+                    )));
                 }
                 let plane = make_sketch_plane_from_orientation(plane.info.into_plane_data(), exec_state, args).await?;
                 Ok(SketchSurface::Plane(plane))
@@ -1200,10 +1198,10 @@ async fn inner_start_sketch_on(
         }
         SketchData::Solid(solid) => {
             let Some(tag) = face else {
-                return Err(KclError::Type(KclErrorDetails {
-                    message: "Expected a tag for the face to sketch on".to_string(),
-                    source_ranges: vec![args.source_range],
-                }));
+                return Err(KclError::Type(KclErrorDetails::new(
+                    "Expected a tag for the face to sketch on".to_string(),
+                    vec![args.source_range],
+                )));
             };
             let face = start_sketch_on_face(solid, tag, exec_state, args).await?;
 
@@ -1715,12 +1713,10 @@ pub(crate) async fn inner_arc(
             absolute_arc(&args, id, exec_state, sketch, from, interior_absolute, end_absolute, tag).await
         }
         _ => {
-            Err(KclError::Type(KclErrorDetails {
-                message:
-                    "Invalid combination of arguments. Either provide (angleStart, angleEnd, radius) or (endAbsolute, interiorAbsolute)"
-                        .to_string(),
-                source_ranges: vec![args.source_range],
-            }))
+            Err(KclError::Type(KclErrorDetails::new(
+                "Invalid combination of arguments. Either provide (angleStart, angleEnd, radius) or (endAbsolute, interiorAbsolute)".to_owned(),
+                vec![args.source_range],
+            )))
         }
     }
 }
@@ -1804,10 +1800,10 @@ pub async fn relative_arc(
     let radius = radius.to_length_units(from.units);
     let (center, end) = arc_center_and_end(from.ignore_units(), a_start, a_end, radius);
     if a_start == a_end {
-        return Err(KclError::Type(KclErrorDetails {
-            message: "Arc start and end angles must be different".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Type(KclErrorDetails::new(
+            "Arc start and end angles must be different".to_string(),
+            vec![args.source_range],
+        )));
     }
     let ccw = a_start < a_end;
 
@@ -1958,19 +1954,18 @@ async fn inner_tangential_arc(
             let data = TangentialArcData::RadiusAndOffset { radius, offset: angle };
             inner_tangential_arc_radius_angle(data, sketch, tag, exec_state, args).await
         }
-        (Some(_), Some(_), None, None) => Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message: "You cannot give both `end` and `endAbsolute` params, you have to choose one or the other"
-                .to_owned(),
-        })),
-        (None, None, Some(_), None) | (None, None, None, Some(_)) => Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message: "You must supply both `radius` and `angle` arguments".to_owned(),
-        })),
-        (_, _, _, _) => Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message: "You must supply `end`, `endAbsolute`, or both `radius` and `angle` arguments".to_owned(),
-        })),
+        (Some(_), Some(_), None, None) => Err(KclError::Semantic(KclErrorDetails::new(
+            "You cannot give both `end` and `endAbsolute` params, you have to choose one or the other".to_owned(),
+            vec![args.source_range],
+        ))),
+        (None, None, Some(_), None) | (None, None, None, Some(_)) => Err(KclError::Semantic(KclErrorDetails::new(
+            "You must supply both `radius` and `angle` arguments".to_owned(),
+            vec![args.source_range],
+        ))),
+        (_, _, _, _) => Err(KclError::Semantic(KclErrorDetails::new(
+            "You must supply `end`, `endAbsolute`, or both `radius` and `angle` arguments".to_owned(),
+            vec![args.source_range],
+        ))),
     }
 }
 
@@ -2121,19 +2116,17 @@ async fn inner_tangential_arc_to_point(
     });
 
     if result.center[0].is_infinite() {
-        return Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message:
+        return Err(KclError::Semantic(KclErrorDetails::new(
             "could not sketch tangential arc, because its center would be infinitely far away in the X direction"
                 .to_owned(),
-        }));
+            vec![args.source_range],
+        )));
     } else if result.center[1].is_infinite() {
-        return Err(KclError::Semantic(KclErrorDetails {
-            source_ranges: vec![args.source_range],
-            message:
+        return Err(KclError::Semantic(KclErrorDetails::new(
             "could not sketch tangential arc, because its center would be infinitely far away in the Y direction"
                 .to_owned(),
-        }));
+            vec![args.source_range],
+        )));
     }
 
     let delta = if is_absolute {

rust/kcl-lib/src/std/sweep.rs

@@ -193,10 +193,10 @@ async fn inner_sweep(
         Some("sketchPlane") => RelativeTo::SketchPlane,
         Some("trajectoryCurve") | None => RelativeTo::TrajectoryCurve,
         Some(_) => {
-            return Err(KclError::Syntax(crate::errors::KclErrorDetails {
-                source_ranges: vec![args.source_range],
-                message: "If you provide relativeTo, it must either be 'sketchPlane' or 'trajectoryCurve'".to_owned(),
-            }))
+            return Err(KclError::Syntax(crate::errors::KclErrorDetails::new(
+                "If you provide relativeTo, it must either be 'sketchPlane' or 'trajectoryCurve'".to_owned(),
+                vec![args.source_range],
+            )))
         }
     };
 

rust/kcl-lib/src/std/transform.rs

@@ -36,10 +36,10 @@ pub async fn scale(exec_state: &mut ExecState, args: Args) -> Result<KclValue, K
 
     // Ensure at least one scale value is provided.
     if scale_x.is_none() && scale_y.is_none() && scale_z.is_none() {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message: "Expected `x`, `y`, or `z` to be provided.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            "Expected `x`, `y`, or `z` to be provided.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let objects = inner_scale(
@@ -219,10 +219,10 @@ pub async fn translate(exec_state: &mut ExecState, args: Args) -> Result<KclValu
 
     // Ensure at least one translation value is provided.
     if translate_x.is_none() && translate_y.is_none() && translate_z.is_none() {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message: "Expected `x`, `y`, or `z` to be provided.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            "Expected `x`, `y`, or `z` to be provided.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     let objects = inner_translate(objects, translate_x, translate_y, translate_z, global, exec_state, args).await?;
@@ -452,82 +452,82 @@ pub async fn rotate(exec_state: &mut ExecState, args: Args) -> Result<KclValue,
 
     // Check if no rotation values are provided.
     if roll.is_none() && pitch.is_none() && yaw.is_none() && axis.is_none() && angle.is_none() {
-        return Err(KclError::Semantic(KclErrorDetails {
-            message: "Expected `roll`, `pitch`, and `yaw` or `axis` and `angle` to be provided.".to_string(),
-            source_ranges: vec![args.source_range],
-        }));
+        return Err(KclError::Semantic(KclErrorDetails::new(
+            "Expected `roll`, `pitch`, and `yaw` or `axis` and `angle` to be provided.".to_string(),
+            vec![args.source_range],
+        )));
     }
 
     // If they give us a roll, pitch, or yaw, they must give us at least one of them.
     if roll.is_some() || pitch.is_some() || yaw.is_some() {
         // Ensure they didn't also provide an axis or angle.
         if axis.is_some() || angle.is_some() {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "Expected `axis` and `angle` to not be provided when `roll`, `pitch`, and `yaw` are provided."
-                    .to_string(),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "Expected `axis` and `angle` to not be provided when `roll`, `pitch`, and `yaw` are provided."
+                    .to_owned(),
+                vec![args.source_range],
+            )));
         }
     }
 
     // If they give us an axis or angle, they must give us both.
     if axis.is_some() || angle.is_some() {
         if axis.is_none() {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "Expected `axis` to be provided when `angle` is provided.".to_string(),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "Expected `axis` to be provided when `angle` is provided.".to_string(),
+                vec![args.source_range],
+            )));
         }
         if angle.is_none() {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "Expected `angle` to be provided when `axis` is provided.".to_string(),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "Expected `angle` to be provided when `axis` is provided.".to_string(),
+                vec![args.source_range],
+            )));
         }
 
         // Ensure they didn't also provide a roll, pitch, or yaw.
         if roll.is_some() || pitch.is_some() || yaw.is_some() {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: "Expected `roll`, `pitch`, and `yaw` to not be provided when `axis` and `angle` are provided."
-                    .to_string(),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                "Expected `roll`, `pitch`, and `yaw` to not be provided when `axis` and `angle` are provided."
+                    .to_owned(),
+                vec![args.source_range],
+            )));
         }
     }
 
     // Validate the roll, pitch, and yaw values.
     if let Some(roll) = &roll {
         if !(-360.0..=360.0).contains(&roll.n) {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Expected roll to be between -360 and 360, found `{}`", roll.n),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Expected roll to be between -360 and 360, found `{}`", roll.n),
+                vec![args.source_range],
+            )));
         }
     }
     if let Some(pitch) = &pitch {
         if !(-360.0..=360.0).contains(&pitch.n) {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Expected pitch to be between -360 and 360, found `{}`", pitch.n),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Expected pitch to be between -360 and 360, found `{}`", pitch.n),
+                vec![args.source_range],
+            )));
         }
     }
     if let Some(yaw) = &yaw {
         if !(-360.0..=360.0).contains(&yaw.n) {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Expected yaw to be between -360 and 360, found `{}`", yaw.n),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Expected yaw to be between -360 and 360, found `{}`", yaw.n),
+                vec![args.source_range],
+            )));
         }
     }
 
     // Validate the axis and angle values.
     if let Some(angle) = &angle {
         if !(-360.0..=360.0).contains(&angle.n) {
-            return Err(KclError::Semantic(KclErrorDetails {
-                message: format!("Expected angle to be between -360 and 360, found `{}`", angle.n),
-                source_ranges: vec![args.source_range],
-            }));
+            return Err(KclError::Semantic(KclErrorDetails::new(
+                format!("Expected angle to be between -360 and 360, found `{}`", angle.n),
+                vec![args.source_range],
+            )));
         }
     }
 

rust/kcl-lib/src/unparser.rs

@@ -881,10 +881,10 @@ pub async fn walk_dir(dir: &std::path::PathBuf) -> Result<Vec<std::path::PathBuf
 #[cfg(not(target_arch = "wasm32"))]
 pub async fn recast_dir(dir: &std::path::Path, options: &crate::FormatOptions) -> Result<(), anyhow::Error> {
     let files = walk_dir(&dir.to_path_buf()).await.map_err(|err| {
-        crate::KclError::Internal(crate::errors::KclErrorDetails {
-            message: format!("Failed to walk directory `{}`: {:?}", dir.display(), err),
-            source_ranges: vec![crate::SourceRange::default()],
-        })
+        crate::KclError::Internal(crate::errors::KclErrorDetails::new(
+            format!("Failed to walk directory `{}`: {:?}", dir.display(), err),
+            vec![crate::SourceRange::default()],
+        ))
     })?;
 
     let futures = files

rust/kcl-lib/src/walk/import_graph.rs

@@ -96,11 +96,11 @@ fn topsort(all_modules: &[&str], graph: Graph) -> Result<Vec<Vec<String>>, KclEr
         if stage_modules.is_empty() {
             waiting_modules.sort();
 
-            return Err(KclError::ImportCycle(KclErrorDetails {
-                message: format!("circular import of modules not allowed: {}", waiting_modules.join(", ")),
+            return Err(KclError::ImportCycle(KclErrorDetails::new(
+                format!("circular import of modules not allowed: {}", waiting_modules.join(", ")),
                 // TODO: we can get the right import lines from the AST, but we don't
-                source_ranges: vec![SourceRange::default()],
-            }));
+                vec![SourceRange::default()],
+            )));
         }
 
         // not strictly needed here, but perhaps helpful to avoid thinking
@@ -137,20 +137,20 @@ pub(crate) fn import_dependencies(repr: &ModuleRepr, ctx: &ExecutorContext) -> R
                     // This is a bit of a hack, but it works for now.
                     ret.lock()
                         .map_err(|err| {
-                            KclError::Internal(KclErrorDetails {
-                                message: format!("Failed to lock mutex: {}", err),
-                                source_ranges: Default::default(),
-                            })
+                            KclError::Internal(KclErrorDetails::new(
+                                format!("Failed to lock mutex: {}", err),
+                                Default::default(),
+                            ))
                         })?
                         .push((filename.to_string(), is.clone(), resolved_path));
                 }
                 ImportPath::Foreign { path } => {
                     ret.lock()
                         .map_err(|err| {
-                            KclError::Internal(KclErrorDetails {
-                                message: format!("Failed to lock mutex: {}", err),
-                                source_ranges: Default::default(),
-                            })
+                            KclError::Internal(KclErrorDetails::new(
+                                format!("Failed to lock mutex: {}", err),
+                                Default::default(),
+                            ))
                         })?
                         .push((path.to_string(), is.clone(), resolved_path));
                 }
@@ -169,10 +169,10 @@ pub(crate) fn import_dependencies(repr: &ModuleRepr, ctx: &ExecutorContext) -> R
     walk(ret.clone(), prog.into(), ctx)?;
 
     let ret = ret.lock().map_err(|err| {
-        KclError::Internal(KclErrorDetails {
-            message: format!("Failed to lock mutex: {}", err),
-            source_ranges: Default::default(),
-        })
+        KclError::Internal(KclErrorDetails::new(
+            format!("Failed to lock mutex: {}", err),
+            Default::default(),
+        ))
     })?;
 
     Ok(ret.clone())
@@ -213,10 +213,10 @@ pub(crate) async fn import_universe(
 
         let repr = {
             let Some(module_info) = exec_state.get_module(module_id) else {
-                return Err(KclError::Internal(KclErrorDetails {
-                    message: format!("Module {} not found", module_id),
-                    source_ranges: vec![import_stmt.into()],
-                }));
+                return Err(KclError::Internal(KclErrorDetails::new(
+                    format!("Module {} not found", module_id),
+                    vec![import_stmt.into()],
+                )));
             };
             module_info.repr.clone()
         };

src/components/ModelingSidebar/ModelingPanes/index.tsx

@@ -118,7 +118,9 @@ export const sidebarPanes: SidebarPane[] = [
     keybinding: 'Shift + C',
     showBadge: {
       value: ({ kclContext }) => {
-        return kclContext.diagnostics.length
+        return kclContext.diagnostics.filter(
+          (diagnostic) => diagnostic.severity === 'error'
+        ).length
       },
       onClick: (e) => {
         e.preventDefault()

src/lang/errors.test.ts

@@ -12,6 +12,7 @@ describe('test kclErrToDiagnostic', () => {
         kind: 'semantic',
         msg: 'Semantic error',
         sourceRange: topLevelRange(0, 1),
+        kclBacktrace: [],
         nonFatal: [],
         operations: [],
         artifactCommands: [],
@@ -25,6 +26,7 @@ describe('test kclErrToDiagnostic', () => {
         kind: 'type',
         msg: 'Type error',
         sourceRange: topLevelRange(4, 5),
+        kclBacktrace: [],
         nonFatal: [],
         operations: [],
         artifactCommands: [],

src/lang/errors.ts

@@ -18,12 +18,14 @@ import type { SourceRange } from '@rust/kcl-lib/bindings/SourceRange'
 import { defaultArtifactGraph } from '@src/lang/std/artifactGraph'
 import { isTopLevelModule } from '@src/lang/util'
 import type { ArtifactGraph } from '@src/lang/wasm'
+import type { BacktraceItem } from '@rust/kcl-lib/bindings/BacktraceItem'
 
 type ExtractKind<T> = T extends { kind: infer K } ? K : never
 export class KCLError extends Error {
   kind: ExtractKind<RustKclError> | 'name'
   sourceRange: SourceRange
   msg: string
+  kclBacktrace: BacktraceItem[]
   nonFatal: CompilationError[]
   operations: Operation[]
   artifactCommands: ArtifactCommand[]
@@ -35,7 +37,8 @@ export class KCLError extends Error {
     kind: ExtractKind<RustKclError> | 'name',
     msg: string,
     sourceRange: SourceRange,
-    nonFatal: CompilationError[] = [],
+    kclBacktrace: BacktraceItem[],
+    nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
     artifactGraph: ArtifactGraph,
@@ -46,6 +49,7 @@ export class KCLError extends Error {
     this.kind = kind
     this.msg = msg
     this.sourceRange = sourceRange
+    this.kclBacktrace = kclBacktrace
     this.nonFatal = nonFatal
     this.operations = operations
     this.artifactCommands = artifactCommands
@@ -60,6 +64,7 @@ export class KCLLexicalError extends KCLError {
   constructor(
     msg: string,
     sourceRange: SourceRange,
+    kclBacktrace: BacktraceItem[],
     nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
@@ -71,6 +76,7 @@ export class KCLLexicalError extends KCLError {
       'lexical',
       msg,
       sourceRange,
+      kclBacktrace,
       nonFatal,
       operations,
       artifactCommands,
@@ -86,6 +92,7 @@ export class KCLInternalError extends KCLError {
   constructor(
     msg: string,
     sourceRange: SourceRange,
+    kclBacktrace: BacktraceItem[],
     nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
@@ -97,6 +104,7 @@ export class KCLInternalError extends KCLError {
       'internal',
       msg,
       sourceRange,
+      kclBacktrace,
       nonFatal,
       operations,
       artifactCommands,
@@ -112,6 +120,7 @@ export class KCLSyntaxError extends KCLError {
   constructor(
     msg: string,
     sourceRange: SourceRange,
+    kclBacktrace: BacktraceItem[],
     nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
@@ -123,6 +132,7 @@ export class KCLSyntaxError extends KCLError {
       'syntax',
       msg,
       sourceRange,
+      kclBacktrace,
       nonFatal,
       operations,
       artifactCommands,
@@ -138,6 +148,7 @@ export class KCLSemanticError extends KCLError {
   constructor(
     msg: string,
     sourceRange: SourceRange,
+    kclBacktrace: BacktraceItem[],
     nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
@@ -149,6 +160,7 @@ export class KCLSemanticError extends KCLError {
       'semantic',
       msg,
       sourceRange,
+      kclBacktrace,
       nonFatal,
       operations,
       artifactCommands,
@@ -164,6 +176,7 @@ export class KCLTypeError extends KCLError {
   constructor(
     msg: string,
     sourceRange: SourceRange,
+    kclBacktrace: BacktraceItem[],
     nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
@@ -175,6 +188,7 @@ export class KCLTypeError extends KCLError {
       'type',
       msg,
       sourceRange,
+      kclBacktrace,
       nonFatal,
       operations,
       artifactCommands,
@@ -190,6 +204,7 @@ export class KCLIoError extends KCLError {
   constructor(
     msg: string,
     sourceRange: SourceRange,
+    kclBacktrace: BacktraceItem[],
     nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
@@ -201,6 +216,7 @@ export class KCLIoError extends KCLError {
       'io',
       msg,
       sourceRange,
+      kclBacktrace,
       nonFatal,
       operations,
       artifactCommands,
@@ -216,6 +232,7 @@ export class KCLUnexpectedError extends KCLError {
   constructor(
     msg: string,
     sourceRange: SourceRange,
+    kclBacktrace: BacktraceItem[],
     nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
@@ -227,6 +244,7 @@ export class KCLUnexpectedError extends KCLError {
       'unexpected',
       msg,
       sourceRange,
+      kclBacktrace,
       nonFatal,
       operations,
       artifactCommands,
@@ -242,6 +260,7 @@ export class KCLValueAlreadyDefined extends KCLError {
   constructor(
     key: string,
     sourceRange: SourceRange,
+    kclBacktrace: BacktraceItem[],
     nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
@@ -253,6 +272,7 @@ export class KCLValueAlreadyDefined extends KCLError {
       'name',
       `Key ${key} was already defined elsewhere`,
       sourceRange,
+      kclBacktrace,
       nonFatal,
       operations,
       artifactCommands,
@@ -268,6 +288,7 @@ export class KCLUndefinedValueError extends KCLError {
   constructor(
     key: string,
     sourceRange: SourceRange,
+    kclBacktrace: BacktraceItem[],
     nonFatal: CompilationError[],
     operations: Operation[],
     artifactCommands: ArtifactCommand[],
@@ -279,6 +300,7 @@ export class KCLUndefinedValueError extends KCLError {
       'name',
       `Key ${key} has not been defined`,
       sourceRange,
+      kclBacktrace,
       nonFatal,
       operations,
       artifactCommands,
@@ -308,6 +330,7 @@ export function lspDiagnosticsToKclErrors(
           [],
           [],
           [],
+          [],
           defaultArtifactGraph(),
           {},
           null
@@ -336,16 +359,44 @@ export function kclErrorsToDiagnostics(
   let nonFatal: CodeMirrorDiagnostic[] = []
   const errs = errors
     ?.filter((err) => isTopLevelModule(err.sourceRange))
-    .map((err): CodeMirrorDiagnostic => {
+    .flatMap((err) => {
+      const diagnostics: CodeMirrorDiagnostic[] = []
+      let message = err.msg
+      if (err.kclBacktrace.length > 0) {
+        // Show the backtrace in the error message.
+        for (let i = 0; i < err.kclBacktrace.length; i++) {
+          const item = err.kclBacktrace[i]
+          if (
+            i > 0 &&
+            isTopLevelModule(item.sourceRange) &&
+            item.sourceRange[0] !== err.sourceRange[0] &&
+            item.sourceRange[1] !== err.sourceRange[1]
+          ) {
+            diagnostics.push({
+              from: item.sourceRange[0],
+              to: item.sourceRange[1],
+              message: 'Part of the error backtrace',
+              severity: 'hint',
+            })
+          }
+          if (i === err.kclBacktrace.length - 1 && !item.fnName) {
+            // The top-level doesn't have a name.
+            break
+          }
+          const name = item.fnName ? `${item.fnName}()` : '(anonymous)'
+          message += `\n${name}`
+        }
+      }
       if (err.nonFatal.length > 0) {
         nonFatal = nonFatal.concat(compilationErrorsToDiagnostics(err.nonFatal))
       }
-      return {
+      diagnostics.push({
         from: err.sourceRange[0],
         to: err.sourceRange[1],
-        message: err.msg,
+        message,
         severity: 'error',
-      }
+      })
+      return diagnostics
     })
   return errs.concat(nonFatal)
 }

src/lang/executor.test.ts

@@ -464,6 +464,7 @@ theExtrude = startSketchOn(XY)
         expect.any(Object),
         expect.any(Object),
         expect.any(Object),
+        expect.any(Object),
         null
       )
     )

src/lang/wasm.test.ts

@@ -47,11 +47,11 @@ it('formats numbers with units', () => {
 describe('test errFromErrWithOutputs', () => {
   it('converts KclErrorWithOutputs to KclError', () => {
     const blob =
-      '{"error":{"kind":"internal","sourceRanges":[],"msg":"Cache busted"},"nonFatal":[],"operations":[],"artifactCommands":[],"artifactGraph":{"map":{}},"filenames":{},"sourceFiles":{},"defaultPlanes":null}'
+      '{"error":{"kind":"internal","sourceRanges":[],"backtrace":[],"msg":"Cache busted"},"nonFatal":[],"operations":[],"artifactCommands":[],"artifactGraph":{"map":{}},"filenames":{},"sourceFiles":{},"defaultPlanes":null}'
     const error = errFromErrWithOutputs(blob)
     const errorStr = JSON.stringify(error)
     expect(errorStr).toEqual(
-      '{"kind":"internal","sourceRange":[0,0,0],"msg":"Cache busted","nonFatal":[],"operations":[],"artifactCommands":[],"artifactGraph":{},"filenames":{},"defaultPlanes":null}'
+      '{"kind":"internal","sourceRange":[0,0,0],"msg":"Cache busted","kclBacktrace":[],"nonFatal":[],"operations":[],"artifactCommands":[],"artifactGraph":{},"filenames":{},"defaultPlanes":null}'
     )
   })
 })

src/lang/wasm.ts

@@ -164,17 +164,15 @@ function bestSourceRange(error: RustKclError): SourceRange {
   }
 
   // When there's an error, the call stack is unwound, and the locations are
-  // built up from deepest location to shallowest. So the shallowest call is
-  // last. That's the most useful to the user.
-  for (let i = error.sourceRanges.length - 1; i >= 0; i--) {
-    const range = error.sourceRanges[i]
+  // built up from deepest location to shallowest. So the deepest call is first.
+  for (const range of error.sourceRanges) {
     // Skip ranges pointing into files that aren't the top-level module.
     if (isTopLevelModule(range)) {
       return sourceRangeFromRust(range)
     }
   }
-  // We didn't find a top-level module range, so just use the last one.
-  return sourceRangeFromRust(error.sourceRanges[error.sourceRanges.length - 1])
+  // We didn't find a top-level module range, so just use the first one.
+  return sourceRangeFromRust(error.sourceRanges[0])
 }
 
 const splitErrors = (
@@ -248,6 +246,7 @@ export const parse = (code: string | Error): ParseResult | Error => {
       [],
       [],
       [],
+      [],
       defaultArtifactGraph(),
       {},
       null
@@ -402,6 +401,7 @@ export const errFromErrWithOutputs = (e: any): KCLError => {
     parsed.error.kind,
     parsed.error.msg,
     bestSourceRange(parsed.error),
+    parsed.error.backtrace,
     parsed.nonFatal,
     parsed.operations,
     parsed.artifactCommands,