Dart-code: Crashing during hot reload when --track-widget-creation is enabled

[c4talyst]

vscode extension Dart was upgraded to 2.17.0. Running with "Start Debugging F5". Using iOS simulator, iPhone X, iOS 11.1. Any minor change, even adding in whitespace, and Saving (cmd-s), causing a hot reload, results in the following

../../third_party/dart/runtime/vm/object.h: 8847: error: Handle check failed: saw Instance of 'HomePage' expected Closure
Dumping native stack trace for thread 5c03
[0x00000001008ac0d4] dart::Profiler::DumpStackTrace(void*)
[0x00000001008ac0d4] dart::Profiler::DumpStackTrace(void*)
[0x0000000100b20142] dart::Assert::Fail(char const*, ...)
[0x0000000100903f3b] dart::DRT_InvokeClosureNoSuchMethod(dart::NativeArguments)
[0x000000011678085b] [Stub] CallToRuntime
[0x0000000116782dc4] [Stub] CallClosureNoSuchMethod
[0x000000011f3be9cb] new HomePage
[0x000000011f3be69a] MyApp.build
[0x000000011c179714] StatelessElement.build
[0x000000011c178a5e] ComponentElement.performRebuild
[0x000000011c177bc1] Element.rebuild
[0x000000011c16b1d0] BuildOwner.buildScope
[0x00000001169c1370] _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.drawFrame
[0x00000001169c0f68] _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback
[0x00000001169c0d7f] _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback
[0x00000001188e68b5] _Closure.call
[0x00000001169c0796] _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback
[0x000000011c480b28] _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame
[0x000000011ca2680b] _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame.<anonymous closure>
[0x00000001188c0512] _Closure.call
[0x000000011cf7f96d] Timer._createTimer.<anonymous closure>
[0x00000001188e68b5] _Closure.call
[0x000000011cf7ea75] _Timer._runTimers
[0x00000001169bdc32] _Timer._handleMessage
[0x00000001169bd73b] _Timer._handleMessage
[0x00000001188e68b5] _Closure.call
[0x00000001188e67bc] _RawReceivePortImpl._handleMessage
[0x0000000116780ce3] [Stub] InvokeDartCode
[0x00000001007637c9] dart::DartEntry::InvokeFunction(dart::Function const&, dart::Array const&, dart::Array const&, unsigned long)
[0x0000000100766f0e] dart::DartLibraryCalls::HandleMessage(dart::Object const&, dart::Instance const&)
[0x0000000100792ed6] dart::IsolateMessageHandler::HandleMessage(dart::Message*)
[0x00000001007bdfee] dart::MessageHandler::HandleMessages(dart::MonitorLocker*, bool, bool)
[0x00000001007be0f0] dart::MessageHandler::HandleNextMessage()
[0x0000000100aa0175] Dart_HandleMessage
[0x00000001005ef285] tonic::DartMessageHandler::OnHandleMessage(tonic::DartState*)
[0x000000010027c222] fml::MessageLoopImpl::RunExpiredTasks()
[0x000000010027ef1a] fml::MessageLoopDarwin::OnTimerFire(__CFRunLoopTimer*, fml::MessageLoopDarwin*)
[0x00000001028832a4] __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__
[0x0000000102882f62] __CFRunLoopDoTimer
[0x0000000102882b1a] __CFRunLoopDoTimers
[0x000000010287a534] __CFRunLoopRun
[0x00000001028799b9] CFRunLoopRunSpecific
[0x000000010027f06b] fml::MessageLoopDarwin::Run()
[0x000000010027c359] fml::MessageLoopImpl::DoRun()
[0x000000010027ea70] std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::Thread::Thread(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0> >(void*, void*)
[0x0000000107ec8661] _pthread_body
[0x0000000107ec850d] _pthread_body
[0x0000000107ec7bf9] thread_start
Lost connection to device.
-- End of DumpStackTrace
Exited (sigterm)

Also logged here https://github.com/flutter/flutter/issues/20191. Could this be related to the "Inspect Flutter Widget" feature added?

[DanTup]

That's the only thing I could think could have caused this to appear in this version, since there's not really anything else that'd affect how flutter run behaves.

Can you try setting "dart.flutterTrackWidgetCreation": false in your VS Code settings and see if that fixes things?

[c4talyst]

The "dart.flutterTrackWidgetCreation": false setting fixed it. Thanks @DanTup

[c4talyst]

Yes, this happens in a new project too.

VSCode: 1.25.1
Dart extension: 2.17.0

Flutter doctor

I haven't set this machine up for Android dev yet.

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v0.5.1, on Mac OS X 10.13.5 17F77, locale en-ZA)
[!] Android toolchain - develop for Android devices (Android SDK 28.0.1)
    ✗ Android licenses not accepted.  To resolve this, run: flutter doctor --android-licenses
[✓] iOS toolchain - develop for iOS devices (Xcode 9.1)
[✓] Android Studio (version 3.1)
    ✗ Flutter plugin not installed; this adds Flutter specific functionality.
    ✗ Dart plugin not installed; this adds Dart specific functionality.
[!] VS Code (version 1.25.1)
[✓] Connected devices (2 available)

! Doctor found issues in 2 categories.

[DanTup]

Thanks; I'll try and repro in the morning. If you're able to check if it happens on dev or master channels, that'd be useful to know too.

[DanTup]

I'm going to disable this by default (#1138) while this is investigated. It's possible a flutter clean will fix it if you want to try that.

[DanTup]

I've pushed out v2.17.1 which disables this by default while it's investigated. You may wish to try turning it on and doing flutter clean. I'll re-enable by default once it works reliably.

Leaving this issue open to track the proper fix.

[Narumikun]

@DanTup The same problem occurs in Android studio 3 (macOS). I wonder how I set "dart.flutterTrackWidgetCreation": false in Android Studio 3.

[DanTup]

@Narumikun Thanks for the info. I believe there is a way to disable track-widget-creation in IntelliJ but I'm not sure where it is but I'd guess somewhere in the Flutter settings in IntelliJ - I don't know if it's called "Track Widget Creation" or just something related to enabling the Widget Inspector. @devoncarew or @jacob314 may be able to confirm.

[devoncarew]

Yup, there is a way - from the preferences, Languages and frameworks, Flutter, you can disable the flag to track widget creation.

[LJame]

@Narumikun The same problem occurs in Android studio 3 (macOS). I wonder how I set "dart.flutterTrackWidgetCreation": false in Android Studio 3.

The same problem occurs in Android studio 3 (macOS). I wonder how I set "dart.flutterTrackWidgetCreation": false in Android Studio 3.
halo you solve it?The same problem occurs.

[DanTup]

@LJame the crash that this is case referred to was actually fixed prior to Flutter 1.0 (so we re-enabled it by default in #1277) though I forgot to resolve this. If you're on Flutter >= 1.0 and seeing crashes only when track-widget-creation is enabled, would you mind opening at https://github.com/flutter/flutter?

If you do need to disable it, the instructions Devon gave above apply to both IntelliJ and Android Studio:

Hope this helps!