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.

Blockly workspace tidak ikut resize saat panel di-drag

Symptom: Drag vertical/horizontal divider, Blockly canvas tidak resize — tetap ukuran lama.

Cause: resizable-panels.js hanya panggil Blockly.svgResize() tanpa update dimensi #blockly-div yang position: absolute.

Solution: Update #blockly-div width/height dari #blockly-area offsetWidth/Height sebelum svgResize. File: core/resizable-panels.js (mousemove handler).

App freeze saat kedua program pakai while(true)

Symptom: App tidak responsif (freeze) saat main_program dan main_hmi_program keduanya punya while(true) loop.

Cause: User menulis while(true) di main_hmi_program. Auto-wrapper menambah outer while-loop, tapi inner while(true) dengan HMI calls (synchronous) tidak pernah yield ke event loop.

Solution: HMI shadowed highlightBlock diubah dari sync no-op ke async function dengan stopRequested check. Setiap await highlightBlock() di generated code yield ke event loop + bisa di-stop. File: core/debug-engine.js — _runConcurrent() dan _runDebugConcurrent().

Variabel tidak ter-share antara main dan HMI program

Symptom: Variable yang di-set di main_program tidak terlihat di main_hmi_program (tetap default value).

Cause: definitions (berisi var led;) di-eval di dua IIFE terpisah → dua scope terpisah.

Solution: Gabung kedua program dalam SATU eval — outer IIFE berisi definitions, dua inner IIFE (main + HMI) close over shared scope. File: core/debug-engine.js — _runConcurrent() dan _runDebugConcurrent().

Delete HMI block tidak menghapus preview widget; undo muncul blank widget

Symptom: Hapus HMI block → widget masih ada di HMI panel. Undo → widget muncul tapi kosong.

Cause: _blockToWidget Map di hmi-preview.js kehilangan sinkronisasi saat undo/redo. Blockly events pada undo tidak selalu re-add mapping.

Solution: Tambah _reconcile() dengan 100ms debounce setelah setiap workspace event. Fungsi ini compare HMI blocks di workspace vs _blockToWidget map, hapus widget orphan, tambah widget yang belum ter-track. File: core/hmi-preview.js.

UI freeze pada while(true) loop di Main Program (polling HMI controls)

Symptom: Main Program dengan while(true) untuk polling HMI.getButton() → seluruh UI freeze, HMI panel tidak update, tombol Stop tidak responsif.

Cause: highlightBlock override hanya yield ke microtask queue. Microtask tidak memberi giliran ke macrotask queue (click events, setTimeout, requestAnimationFrame).

Solution: Tambahkan periodic yield ke macrotask queue (~60Hz) di highlightBlock override. Setiap 16ms, setTimeout(r, 0) memaksa browser memproses macrotask. Diterapkan di _runConcurrent() dan _runSingle(). File: core/debug-engine.js.

HMI Button getButton() selalu return false meskipun sudah diklik

Symptom: while(getButton()!= true) {delay(500);} tidak pernah keluar dari loop.

Cause: HMI loop (~20Hz) memanggil setButton() → _scheduleRender() → _render() menghancurkan DOM button lama dan membuat baru setiap ~50ms. Event click butuh mousedown+mouseup pada elemen DOM yang sama — karena DOM diganti mid-click, click event tidak pernah fire.

Solution: Ganti click → pointerdown di _renderButton(). pointerdown fire langsung saat ditekan tanpa menunggu mouseup. File: core/hmi-manager.js.

HMI Switch/Slider tidak bisa di-toggle/drag — selalu reset ke initial value

Symptom: setSwitch('Switch1', Boolean(led)) dalam HMI loop menimpa user toggle setiap ~50ms. Slider juga reset ke 0 setelah user release.

Cause: HMI loop berjalan 10x lebih cepat dari Main Program. setSwitch() langsung overwrite widget.state, dan setSlider() overwrite _userValue segera setelah _userInteracting = false (mouseup).

Solution: User interaction tracking — state user disimpan terpisah dari programmatic state. Switch: _userState field, tidak ditimpa oleh setSwitch(). Slider: _userHasInteracted flag persist setelah release, mencegah setSlider() overwrite _userValue. File: core/hmi-manager.js.

Dua HMI block dengan nama sama hanya membuat satu widget

Symptom: Drag dua block HMI LED dari toolbox → hanya satu widget muncul di panel (keduanya default ke LED1).

Cause: _widgets Map menggunakan nama sebagai key. Block kedua dengan nama sama hanya update widget yang ada, bukan membuat baru.

Solution: Auto-increment nama di _handleCreate() — jika LED1 sudah dipakai, block baru otomatis menjadi LED2. Block field di-update via setFieldValue(). Juga fix _handleDelete() untuk tidak menghapus widget jika block lain masih menggunakan nama yang sama. File: core/hmi-preview.js.

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