[Linux Desktop]Unhandled Exception: 'package:flutter/src/rendering/mouse_tracker.dart': Failed assertion: line 317 pos 18: 'event is! PointerRemovedEvent': is not true. #100659
Description
Expected results:
I wrote a simple desktop app to exhibit flutter assertion failures in mouse_tracker.dart. These failures occur at startup of the app - not always, but on a high percentage of runs.
Actual results:
Sometimes starts with assertion failures, sometimes not.
The example uses the Google window_size plugin to constrain the app window size, then runs a trivial app consisting of a Listener widget wrapping a Container. I suspect that the problem is with the window_size plugin, since I haven't seen the issue when I comment out the lines of code using it
code sample.
import 'dart:async';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:window_size/window_size.dart';
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
if (Platform.isLinux) {
setWindowMaxSize(const Size(640, 480));
setWindowMinSize(const Size(640, 480));
}
runApp(Listener(onPointerDown: _pointerEventListener,
child: Container()));
}
void _pointerEventListener(PointerEvent event) {
print('Pointer down at: ${event.position}');
}Logs
Launching test/mouse_tracker_bug_test.dart on Linux in debug mode...
Building Linux application...
Debug service listening on ws://127.0.0.1:45687/jLrRROscyPg=/ws
Syncing files to device Linux...
[ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: 'package:flutter/src/rendering/mouse_tracker.dart': Failed assertion: line 317 pos 18: 'event is! PointerRemovedEvent': is not true.
#0 _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:51:61)
#1 _AssertionError._throwNew (dart:core-patch/errors_patch.dart:40:5)
#2 MouseTracker.updateWithEvent.<anonymous closure>.<anonymous closure> (package:flutter/src/rendering/mouse_tracker.dart:317:18)
#3 MouseTracker._deviceUpdatePhase (package:flutter/src/rendering/mouse_tracker.dart:206:9)
#4 MouseTracker.updateWithEvent.<anonymous closure> (package:flutter/src/rendering/mouse_tracker.dart:312:7)
#5 MouseTracker._monitorMouseConnection (package:flutter/src/rendering/mouse_tracker.dart:190:9)
#6 MouseTracker.updateWithEvent (package:flutter/src/rendering/mouse_tracker.dart:311:5)
#7 RendererBinding.dispatchEvent (package:flutter/src/rendering/binding.dart:314:20)
#8 GestureBinding._handlePointerEventImmediately (package:flutter/src/gestures/binding.dart:374:7)
#9 GestureBinding.handlePointerEvent (package:flutter/src/gestures/binding.dart:338:5)
#10 GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:296:7)
#11 GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:279:7)
#12 _rootRunUnary (dart:async/zone.dart:1442:13)
#13 _CustomZone.runUnary (dart:async/zone.dart:1335:19)
#14 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1244:7)
#15 _invoke1 (dart:ui/hooks.dart:170:10)
#16 PlatformDispatcher._dispatchPointerDataPacket (dart:ui/platform_dispatcher.dart:331:7)
#17 _dispatchPointerDataPacket (dart:ui/hooks.dart:94:31)
======== Exception caught by scheduler library =====================================================
The following assertion was thrown during a scheduler callback:
'package:flutter/src/rendering/mouse_tracker.dart': Failed assertion: line 201 pos 12: '!_debugDuringDeviceUpdate': is not true.
Either the assertion indicates an error in the framework itself, or we should provide substantially more information in this error message to help you determine and fix the underlying cause.
In either case, please report this assertion by filing a bug on GitHub:
https://github.com/flutter/flutter/issues/new?template=2_bug.md
When the exception was thrown, this was the stack:
#2 MouseTracker._deviceUpdatePhase (package:flutter/src/rendering/mouse_tracker.dart:201:12)
#3 MouseTracker.updateAllDevices (package:flutter/src/rendering/mouse_tracker.dart:353:5)
#4 RendererBinding._scheduleMouseTrackerUpdate.<anonymous closure> (package:flutter/src/rendering/binding.dart:380:22)
#5 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1144:15)
#6 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1089:9)
#7 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:995:5)
#11 _invoke (dart:ui/hooks.dart:151:10)
#12 PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:308:5)
#13 _drawFrame (dart:ui/hooks.dart:115:31)
(elided 5 frames from class _AssertionError and dart:async)
====================================================================================================
Lost connection to device.
[✓] Flutter (Channel stable, 2.10.3, on Ubuntu 20.04.4 LTS 5.4.0-104-generic, locale
en_US.UTF-8)
• Flutter version 2.10.3 at /home/rhr/Tools/flutter
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 7e9793dee1 (3 weeks ago), 2022-03-02 11:23:12 -0600
• Engine revision bd539267b4
• Dart version 2.16.1
• DevTools version 2.9.2
[✓] Android toolchain - develop for Android devices (Android SDK version 32.0.0)
• Android SDK at /home/rhr/Android/Sdk
• Platform android-32, build-tools 32.0.0
• Java binary at: /usr/lib/jvm/java-11-openjdk-amd64/bin/java
• Java version OpenJDK Runtime Environment (build 11.0.14+9-Ubuntu-0ubuntu2.20.04)
• All Android licenses accepted.
[✓] Chrome - develop for the web
• Chrome at google-chrome
[✓] Linux toolchain - develop for Linux desktop
• clang version 9.0.1-12
• cmake version 3.16.3
• ninja version 1.10.0
• pkg-config version 0.29.1
[!] Android Studio (not installed)
• Android Studio not found; download from https://developer.android.com/studio/index.html
(or visit https://flutter.dev/docs/get-started/install/linux#android-setup for detailed
instructions).
[✓] IntelliJ IDEA Community Edition (version 2021.2)
• IntelliJ at /home/rhr/Tools/idea-IC-212.4416.7
• Flutter plugin version 63.3.3
• Dart plugin version 212.5632
[✓] Connected device (2 available)
• Linux (desktop) • linux • linux-x64 • Ubuntu 20.04.4 LTS 5.4.0-104-generic
• Chrome (web) • chrome • web-javascript • Google Chrome 99.0.4844.74
[✓] HTTP Host Availability
• All required HTTP hosts are available
! Doctor found issues in 1 category.