Reopening the Zone mismatch issue

[hirensamtani]

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Dart

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[✓] Flutter (Channel stable, 3.10.2, on macOS 13.3.1 22E772610a darwin-x64, locale en-IN)
• Flutter version 3.10.2 on channel stable at /Users/hirensamtani/flutter
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 9cd3d0d9ff (6 days ago), 2023-05-23 20:57:28 -0700
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Version

7.6.2

Steps to Reproduce

Simply use WidgetsFlutterBinding.ensureInitialized()

Something like
Future main() async {
// BindingBase.debugZoneErrorsAreFatal = true;
WidgetsFlutterBinding.ensureInitialized();

SystemChrome.setEnabledSystemUIMode(SystemUiMode.manual,
overlays: [SystemUiOverlay.bottom, SystemUiOverlay.top]).then((_) {
SharedPreferences.getInstance().then((prefs) {

  runZonedGuarded<Future<void>>(() async {

    await SentryFlutter.init(
      (options) {
        options.dsn = '//URL HERE';
        // Set tracesSampleRate to 1.0 to capture 100% of transactions for performance monitoring.
        // We recommend adjusting this value in production.
        options.tracesSampleRate = 1.0;
      },
      appRunner: () {
        runApp(MyApp());
      },
    );
  }, (error, stack) {
  });
});

});
}

Expected Result

There should be no warnings. Especially not of Zone mismatch.

Actual Result

The following assertion was thrown during runApp:
Zone mismatch.

The Flutter bindings were initialized in a different zone than is now being used. This will likely cause confusion and bugs as any zone-specific configuration will inconsistently use the configuration of the original binding initialization zone or this zone based on hard-to-predict factors such as which zone was active when a particular callback was set.
It is important to use the same zone when calling ensureInitialized on the binding as when calling runApp later.
To make this warning fatal, set BindingBase.debugZoneErrorsAreFatal to true before the bindings are initialized (i.e. as the first statement in void main() { }).
When the exception was thrown, this was the stack:
#0 BindingBase.debugCheckZone. (package:flutter/src/foundation/binding.dart:497:29)
#1 BindingBase.debugCheckZone (package:flutter/src/foundation/binding.dart:502:6)
#2 runApp (package:flutter/src/widgets/binding.dart:1080:18)
#3 main....

Are you willing to submit a PR?

None

[marandaneto]

For Flutter >= 3.3, you don't need a runZonedGuarded, https://docs.sentry.io/platforms/flutter/usage/#tips-for-catching-errors.
Flutter uses onError https://api.flutter.dev/flutter/dart-ui/PlatformDispatcher/onError.html instead.
The Sentry Flutter SDK already hooks up in the uncaught signal handlers, you don't have to do that yourself.

If you wish to use runZonedGuarded for some reason (I'd be curious if you do), do not use the appRunner callback.
And call Sentry.captureException(...) with the (error, stack) parameters.

Also, The Sentry Flutter SDK also calls WidgetsFlutterBinding.ensureInitialized(); automatically, you don't have to.
If you call this before initing the Sentry Flutter SDK, calling and initing the Sentry SDK has to be within the same zone.
This is a Flutter tooling problem, one of the reasons that PlatformDispatcher#onError exist.

There are more instructions here https://github.com/getsentry/sentry-dart/tree/main/flutter#usage

[cerealexx]

@marandaneto I'm using Sentry.init the regular > 3.3 way, still getting this warn.
I'm also initializing other Firebase services that might be calling ensureInitialized too by themselves, so that might be the problem.
You say

If you call this before initing the Sentry Flutter SDK, calling and initing the Sentry SDK has to be within the same zone.

How can I do that?

[marandaneto]

https://github.com/getsentry/sentry-dart/tree/main/flutter#usage has the answer

import 'dart:async';

import 'package:flutter/widgets.dart';
import 'package:sentry_flutter/sentry_flutter.dart';

Future<void> main() async {
  // creates a zone
  runZonedGuarded(() async {
    // do stuff here
    await SentryFlutter.init(
      (options) {
        options.dsn = 'https://example@sentry.io/add-your-dsn-here';
      },
    );
	// or here
    runApp(MyApp());
  }, (exception, stackTrace) async {
    await Sentry.captureException(exception, stackTrace: stackTrace);
  });
}

ensureInitialized has to be called within the runZonedGuarded