the Dart compiler exited unexpectedly, if I place a breakpoint inside a certain function

[escamoteur]

Unhandled exception:
FormatException: Invalid radix-10 number (at character 1)
package:functional_listener/functional_listener.dart
functional_listener.dart:1
^

#0      int._handleFormatError (dart:core-patch/integers_patch.dart:126:5)
#1      int._parseRadix (dart:core-patch/integers_patch.dart:152:16)

#2      int._parse (dart:core-patch/integers_patch.dart:98:12)
#3      int.parse (dart:core-patch/integers_patch.dart:60:12)
#4      parseDefinitionTypes (package:front_end/src/api_prototype/expression_compilation_tools.dart:113:36)
#5      createDefinitionsWithTypes (package:front_end/src/api_prototype/expression_compilation_tools.dart:32:7)
#6      IncrementalCompiler.compileExpression (package:vm/incremental_compiler.dart:219:50)
#7      FrontendCompiler.compileExpression (package:frontend_server/frontend_server.dart:981:45)
#8      listenAndCompile.<anonymous closure> (package:frontend_server/frontend_server.dart:1452:26)
#9      _RootZone.runUnaryGuarded (dart:async/zone.dart:1594:10)
#10     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
#11     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271:7)
#12     _SinkTransformerStreamSubscription._add (dart:async/stream_transformers.dart:63:11)
#13     _EventSinkWrapper.add (dart:async/stream_transformers.dart:13:11)
#14     _StringAdapterSink.add (dart:convert/string_conversion.dart:228:11)
#15     _LineSplitterSink._addLines (dart:convert/line_splitter.dart:164:13)
#16     _LineSplitterSink.addSlice (dart:convert/line_splitter.dart:131:7)
#17     StringConversionSink.add (dart:convert/string_conversion.dart:39:5)

It only happens when I set a breakpoint inside

if I remove the breakpoint the app doesn't crash.
I also have no idea where I should do an int.parse to get such an exception. also thee reported file as place where it happens doesn't make sense as the listen function only looks like this

  ListenableSubscription listen(
    void Function(T, ListenableSubscription) handler,
  ) {
    final subscription = ListenableSubscription(this);
    subscription.handler = () => handler(this.value, subscription);
    this.addListener(subscription.handler);
    return subscription;
  }

happens on: Flutter (Channel stable, 3.13.1, on Microsoft Windows [Version 10.0.19045.3324], locale de-DE)

[derekxu16]

I created a Flutter app and made the contents of lib/main.dart the following:

import 'package:flutter/material.dart';
import 'package:functional_listener/functional_listener.dart';

class C {
  Object error = 123;
}

void main() {
  final listenable1 = ValueNotifier<C?>(C());
  final listenable2 = ValueNotifier<C>(C());

  final mergedListenable = listenable1.mergeWith([
    listenable2,
  ]);
  final subscription = mergedListenable.listen((x, _) {
    final apiException = x?.error;
    print(apiException);
  });

  listenable1.value = C();

  subscription.cancel();
}

I was able to set a breakpoint on the final apiException = x?.error; line without any problems. I tested on Linux and not Windows though. It would take me a while to get my Windows environment back up-to-date. So first, can you please try this example on Windows? If it works without issue, can you please try writing a minimal reproduction example? It will be hard to fix this bug without one. Thanks!

[escamoteur]

unfortunately I couldn't reproduce it with the example from you. I can still reproduce it in our real app project. Still wondering why it crashes in

#0 int._handleFormatError (dart:core-patch/integers_patch.dart:126:5)

and the stack trace seems to have no connection to my code whatsoever.

Is there anything that I can add to my code to get more details?
Because I have no idea how to reproduce this in a smaller demo project?

[derekxu16]

Since you're using VSCode, can you please follow these instructions and paste the contents of the log here?

[escamoteur]

dart.log

[derekxu16]

Looks like Dart Code is trying to get the value of di, which is making the compiler crash. Is di from a public package or is it something you wrote yourself? And is di the name of a function or the name of a class here?

[escamoteur]

di is a global variable defined in my package watch_it

[escamoteur]

oh, and its a callable class

[mraleph]

/cc @johnniwinther @jensjoha - seems to be related to the expression evaluation.

[johnniwinther]

This might be related to #53453 where the crash also originates from FrontEndCompiler.compileExpression where an invalid definitionTypes value can cause the crash.

@derekxu16 @mraleph Do you know where these values are created?

[johnniwinther]

@aam Do you know where calls to compileExpression comes from when called through Flutter?

I can see the change that added the definitionTypes argument (flutter/flutter@09c0706) but I cannot see any call-site changes other than in tests.

[aam]

@johnniwinther wrote

@aam Do you know where calls to compileExpression comes from when called through Flutter?

I can see the change that added the definitionTypes argument (flutter/flutter@09c0706) but I cannot see any call-site changes other than in tests.

Flutter registers compileExpression service https://github.com/flutter/flutter/blob/master/packages/flutter_tools/lib/src/vmservice.dart#L260, which is invoked by dart vm in https://github.com/dart-lang/sdk/blob/main/sdk/lib/vmservice/running_isolates.dart#L148, which runs when evaluate or evaluateInFrame service requests were made.

[derekxu16]

@johnniwinther do you suspect that your fix for #53453 also fixes this issue?

[johnniwinther]

Yes.

[derekxu16]

@escamoteur if you try switching to the master channel with flutter channel master (https://docs.flutter.dev/release/upgrade#changing-channels), you should not see the same compiler crash anymore. Please let us know if you do.

[escamoteur]

A bit busy at the moment will try today or tomorrow

[escamoteur]

I would really love to but I get suddenly this errors if I switch to master channel

PS C:\Entwicklung\projects\watchcrunch-mobile-v2> flutter run
Launching lib\main.dart on sdk gphone64 x86 64 in debug mode...
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/photo_manager-2.6.0/lib/src/internal/image_provider.dart:61:5: Error: Type 'DecoderCallback' not found.
    DecoderCallback decode, // ignore: deprecated_member_use
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/photo_manager-2.6.0/lib/src/internal/image_provider.dart:86:5: Error: Type 'DecoderCallback' not found.
    DecoderCallback decode, // ignore: deprecated_member_use
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/photo_manager-2.6.0/lib/src/internal/image_provider.dart:61:5: Error: 'DecoderCallback' isn't a type.
    DecoderCallback decode, // ignore: deprecated_member_use
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/photo_manager-2.6.0/lib/src/internal/image_provider.dart:86:5: Error: 'DecoderCallback' isn't a type.
    DecoderCallback decode, // ignore: deprecated_member_use
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/cached_network_image-3.2.3/lib/src/image_provider/cached_network_image_provider.dart:78:54: Error: Type 'DecoderCallback' not found.
      image_provider.CachedNetworkImageProvider key, DecoderCallback decode) {
                                                     ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/cached_network_image-3.2.3/lib/src/image_provider/cached_network_image_provider.dart:99:5: Error: Type 'DecoderCallback' not found.
    DecoderCallback decode,
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/cached_network_image-3.2.3/lib/src/image_provider/cached_network_image_provider.dart:78:54: Error: 'DecoderCallback' isn't a type.
      image_provider.CachedNetworkImageProvider key, DecoderCallback decode) {
                                                     ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/cached_network_image-3.2.3/lib/src/image_provider/cached_network_image_provider.dart:99:5: Error: 'DecoderCallback' isn't a type.
    DecoderCallback decode,
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/cached_network_image-3.2.3/lib/src/image_provider/_image_loader.dart:25:5: Error: Type 'DecoderCallback' not found.
    DecoderCallback decode,
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/cached_network_image-3.2.3/lib/src/image_provider/_image_loader.dart:25:5: Error: 'DecoderCallback' isn't a type.
    DecoderCallback decode,
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/cached_network_image_platform_interface-2.0.0/lib/cached_network_image_platform_interface.dart:29:5: Error: Type 'DecoderCallback' not found.
    DecoderCallback decode,
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/cached_network_image_platform_interface-2.0.0/lib/cached_network_image_platform_interface.dart:29:5: Error: 'DecoderCallback' isn't a type.
    DecoderCallback decode,
    ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/flutter_blurhash-0.7.0/lib/src/blurhash_image.dart:32:48: Error: Type 'DecoderCallback' not found.
  ImageStreamCompleter load(BlurHashImage key, DecoderCallback decode) => OneFrameImageStreamCompleter(_loadAsync(key));
                                               ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/flutter_blurhash-0.7.0/lib/src/blurhash_image.dart:32:48: Error: 'DecoderCallback' isn't a type.
  ImageStreamCompleter load(BlurHashImage key, DecoderCallback decode) => OneFrameImageStreamCompleter(_loadAsync(key));
                                               ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/flutter_blurhash-0.7.0/lib/src/blurhash_widget.dart:218:42: Error: Type 'DecoderCallback' not found.
  ImageStreamCompleter load(UiImage key, DecoderCallback decode) => OneFrameImageStreamCompleter(_loadAsync(key));
                                         ^^^^^^^^^^^^^^^
/C:/Users/escam/AppData/Local/Pub/Cache/hosted/pub.dev/flutter_blurhash-0.7.0/lib/src/blurhash_widget.dart:218:42: Error: 'DecoderCallback' isn't a type.
  ImageStreamCompleter load(UiImage key, DecoderCallback decode) => OneFrameImageStreamCompleter(_loadAsync(key));
                                         ^^^^^^^^^^^^^^^
Target kernel_snapshot failed: Exception


FAILURE: Build completed with 2 failures.

1: Task failed with an exception.
-----------
* Where:
Script 'C:\Users\escam\fvm\versions\3.13.4\packages\flutter_tools\gradle\src\main\groovy\flutter.groovy' line: 1343

* What went wrong:
Execution failed for task ':app:compileFlutterBuildProductionDebug'.
> Process 'command 'C:\Users\escam\fvm\versions\3.13.4\bin\flutter.bat'' finished with non-zero exit value 1

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
==============================================================================

2: Task failed with an exception.
-----------
* What went wrong:
java.lang.StackOverflowError (no error message)

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
==============================================================================

* Get more help at https://help.gradle.org

BUILD FAILED in 5s
Running Gradle task 'assembleDebug'...                              6,5s
Exception: Gradle task assembleDebug failed with exit code 1
PS

[johnniwinther]

@derekxu16 Can we close this, given your verification of the fix for the similar error in #53637 ?

[derekxu16]

@derekxu16 Can we close this, given your verification of the fix for the similar error in #53637 ?

SGTM