amr-ros-k4/docs/troubleshooting.md

Troubleshooting & Known Issues

11. Troubleshooting & Known Issues

"Executor is already spinning" in app.py

Symptom: RuntimeError: Executor is already spinning when Blockly calls execute_action().

Cause: Code calls rclpy.spin_until_future_complete() while a background thread is already spinning the same node.

Solution: Use _wait_for_future() which polls future.done() instead of calling spin. The background thread's spin loop resolves the futures.

"Ignoring unexpected goal response" warnings

Symptom: Warning messages about unexpected goal responses.

Cause: Two executor nodes are running simultaneously on the same action topic.

Solution: Ensure only one executor is running:

pkill -f "executor_node"
pixi run executor

Action result always success=False, message=''

Symptom: Executor logs show successful execution, but the client receives default-constructed results.

Cause: Using MultiThreadedExecutor with ReentrantCallbackGroup on the server side causes result delivery failures with rmw_fastrtps_cpp.

Solution: The executor node uses simple rclpy.spin(node) with the default single-threaded executor. Do not add MultiThreadedExecutor or ReentrantCallbackGroup to executor_node.py.

goal_handle.abort() causes empty results

Symptom: When the executor calls goal_handle.abort() for failed commands, the client receives empty result fields.

Solution: Always call goal_handle.succeed(). The result.success field communicates command-level success/failure.

Tests skipped with "Executor Node tidak ditemukan"

Symptom: All tests show SKIPPED with message about executor not found.

Cause: The executor node is not running in a separate terminal.

Solution:

# Terminal 1
pixi run executor

# Terminal 2
pixi run test

Export/Import button has no effect (force close or nothing happens)

Symptom: Clicking Export or Import either force-closes the app or does nothing.

Cause: Qt file dialogs (QFileDialog, pywebview.create_file_dialog) must run on the Qt main thread. pywebview calls Python API methods from a background thread. Attempting to open a Qt dialog from there causes:

• pywebview.create_file_dialog → deadlock via BlockingQueuedConnection → force close
• QFileDialog via QTimer.singleShot → no effect, because non-QThread background threads have no Qt event loop

Solution: Use tkinter.filedialog — tkinter uses its own Tcl/Tk interpreter, completely separate from Qt. filedialog.asksaveasfilename() blocks the calling background thread until the user responds. Already available in the pixi environment (no extra dependency needed). See _native_save_dialog() in app.py.

pywebview shows "GTK cannot be loaded"

Symptom: Warning about ModuleNotFoundError: No module named 'gi' followed by "Using Qt 5.15".

Impact: This is informational only. pywebview tries GTK first, falls back to Qt (which is installed via pyqtwebengine). The application works correctly with the Qt backend.

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