Crash on Flutter 3.38.4 SIGABRT: Java_com_github_dart_1lang_jni_PortProxyBuilder__1invoke #183729

[orestesgaolin]

Steps to reproduce

Run the Android app on Pixel 7 with Android 16. App includes foreground service that is run 24/7. When coming back to the app following issue occurs. I'm not sure which library we use is failing but we have several 3rd party SDKs using jnigen (e.g. Sentry).

SIGABRT: Abort
  libc                0x740f70b2dc abort
  split_config.arm64_v8a.apk0x7022cd7468 dart::Assert::Fail (assert.cc:54)
  split_config.arm64_v8a.apk0x7022e3e428 Dart_EnterIsolate (dart_api_impl.cc)
  split_config.arm64_v8a.apk0x703be9eb00 Java_com_github_dart_1lang_jni_PortProxyBuilder__1invoke (dartjni.c:430)
  base.odex           0x70e0d3bfb0 null

SIGABRT: Abort
  libc                0x7f61c8c788 abort
  split_config.arm64_v8a.apk0x7ae1ce3468 dart::Assert::Fail (assert.cc:54)
  split_config.arm64_v8a.apk0x7ae1e4a428 Dart_EnterIsolate (dart_api_impl.cc)
  split_config.arm64_v8a.apk0x7ace7d5b00 Java_com_github_dart_1lang_jni_PortProxyBuilder__1invoke (dartjni.c:430)
  base.odex           0x7bab101550 null

From Google Play insights:

../../flutter/third_party/dart/runtime/vm/dart_api_impl.cc: 1541: error: Isolate t is already scheduled on mutator thread 0x<sanitized>, failed to schedule from os thread 0x<sanitized>

Android OS distribution

Timestamp	Type	Category	Level	Message	Data
2026-03-13T20:30:19.423Z	error	exception	error		{"type":"SIGABRT","value":"Abort"}
2026-03-13T20:30:19.417Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"resumed\"}"}
2026-03-13T20:30:19.416Z	navigation	app.lifecycle	info		{"data":"{\"state\":\"foreground\"}"}
2026-03-13T20:30:19.357Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"started\"}"}
2026-03-13T20:30:19.351Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"created\"}"}
2026-03-13T20:30:18.143Z	navigation	app.lifecycle	info		{"data":"{\"state\":\"background\"}"}
2026-03-13T20:30:18.124Z	debug	Logcat	warning	[FBP] invokeMethodUIThread: tried to call method on closed channel: OnDetachedFromEngine	{"data":"{\"tag\":\"[FBP-Android]\"}"}
2026-03-13T20:30:18.057Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"destroyed\"}"}
2026-03-13T20:30:18.053Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"stopped\"}"}
2026-03-13T20:30:17.444Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"paused\"}"}
2026-03-13T20:30:17.108Z	navigation	navigation	info		{"data":"{\"from\":\"/activity/2026-03-13\",\"state\":\"didPop\",\"to\":\"/\"}"}
2026-03-13T20:30:14.405Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"resumed\"}"}
2026-03-13T20:30:14.403Z	system	device.event	info		{"data":"{\"level\":47,\"charging\":false,\"action\":\"BATTERY_CHANGED\"}"}
2026-03-13T20:30:14.401Z	navigation	app.lifecycle	info		{"data":"{\"state\":\"foreground\"}"}
2026-03-13T20:30:14.395Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"started\"}"}
2026-03-13T20:04:53.109Z	navigation	app.lifecycle	info		{"data":"{\"state\":\"background\"}"}
2026-03-13T20:04:53.042Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"saveInstanceState\"}"}
2026-03-13T20:04:53.030Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"stopped\"}"}
2026-03-13T20:04:52.411Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"paused\"}"}
2026-03-13T20:04:41.225Z	navigation	navigation	info		{"data":"{\"from\":\"/activity/search\",\"state\":\"didPop\",\"to\":\"/activity/2026-03-13\"}"}
2026-03-13T20:04:38.634Z	navigation	navigation	info		{"data":"{\"from\":\"/activity/2026-03-13\",\"state\":\"didPush\",\"to\":\"/activity/search\"}"}
2026-03-13T20:04:16.049Z	navigation	navigation	info		{"data":"{\"from\":\"/activity/search\",\"state\":\"didPop\",\"to\":\"/activity/2026-03-13\"}"}
2026-03-13T20:04:12.875Z	navigation	navigation	info		{"data":"{\"from\":\"/activity/2026-03-13\",\"state\":\"didPush\",\"to\":\"/activity/search\"}"}
2026-03-13T20:04:03.675Z	navigation	navigation	info		{"data":"{\"from\":\"/\",\"state\":\"didPush\",\"to\":\"/activity/2026-03-13\"}"}
2026-03-13T20:04:01.319Z	navigation	navigation	info		{"data":"{\"state\":\"didPush\",\"to\":\"/\"}"}
2026-03-13T20:04:01.267Z	system	device.event	info		{"data":"{\"level\":51,\"charging\":false,\"action\":\"BATTERY_CHANGED\"}"}
2026-03-13T20:04:00.983Z	navigation	navigation	info		{"data":"{\"state\":\"didPush\",\"to\":\"/\"}"}
2026-03-13T20:04:00.889Z	navigation	app.lifecycle	info		{"data":"{\"state\":\"foreground\"}"}
2026-03-13T20:04:00.885Z	system	network.event	info		{"data":"{\"upload_bandwidth\":15382,\"action\":\"NETWORK_CAPABILITIES_CHANGED\",\"vpn_active\":false,\"signal_strength\":-68,\"network_type\":\"wifi\",\"download_bandwidth\":39052}"}
2026-03-13T20:04:00.885Z	system	network.event	info		{"data":"{\"action\":\"NETWORK_AVAILABLE\"}"}
2026-03-13T20:04:00.860Z	system	device.event	info		{"data":"{\"level\":51,\"charging\":false,\"action\":\"BATTERY_CHANGED\"}"}
2026-03-13T20:04:00.857Z	system	network.event	info		{"data":"{\"upload_bandwidth\":15382,\"action\":\"NETWORK_CAPABILITIES_CHANGED\",\"vpn_active\":false,\"signal_strength\":-68,\"network_type\":\"wifi\",\"download_bandwidth\":39052}"}
2026-03-13T20:04:00.854Z	navigation	ui.lifecycle	info		{"data":"{\"screen\":\"MainActivity\",\"state\":\"resumed\"}"}

Expected results

Would expect no crash on returning to the app :)

Actual results

App crashes on launch

Code sample

n/a

Screenshots or Video

Logs

Logs

flutter pub deps

deps.txt

List of gradle dependencies

android_dependencies.txt

Flutter Doctor output

Doctor output

[✓] Flutter (Channel stable, 3.38.4, on macOS 15.6.1 24G90 darwin-arm64, locale pl-PL) [435ms]
    • Flutter version 3.38.4 on channel stable at /Users/dominik/fvm/versions/3.38.4
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 66dd93f9a2 (3 months ago), 2025-12-03 14:56:10 -0800
    • Engine revision a5cb96369e
    • Dart version 3.10.3
    • DevTools version 2.51.1
    • Feature flags: enable-web, no-enable-linux-desktop, enable-macos-desktop, no-enable-windows-desktop, enable-android,
      enable-ios, cli-animations, enable-native-assets, omit-legacy-version-file, enable-lldb-debugging

[!] Android toolchain - develop for Android devices (Android SDK version 36.1.0) [6,3s]
    • Android SDK at /Users/dominik/Library/Android/sdk
    • Emulator version 36.4.10.0 (build_id 15004761) (CL:N/A)
    ✗ cmdline-tools component is missing.
      Try installing or updating Android Studio.
      Alternatively, download the tools from https://developer.android.com/studio#command-line-tools-only and make sure to
      set the ANDROID_HOME environment variable.
      See https://developer.android.com/studio/command-line for more details.
    ✗ Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/to/macos-android-setup for more details.

[✓] Xcode - develop for iOS and macOS (Xcode 26.3) [1 370ms]
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 17C529
    • CocoaPods version 1.16.2

[✓] Chrome - develop for the web [6ms]
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Connected device (4 available) [10,2s]
    • SM S911B (mobile)          • RFCW60DP85H               • android-arm64  • Android 16 (API 36)
    • iPhone (wireless) (mobile) • 00008101-0001510C3CF0001E • ios            • iOS 26.3.1 23D8133
    • macOS (desktop)            • macos                     • darwin-arm64   • macOS 15.6.1 24G90 darwin-arm64
    • Chrome (web)               • chrome                    • web-javascript • Google Chrome 146.0.7680.80

[✓] Network resources [252ms]
    • All expected network resources are available.

! Doctor found issues in 1 category.

Related

#2808
flutter/flutter#183729

[liamappelbe]

Interesting. That's one I haven't seen before. Looks like a bug in PortProxyBuilder.invoke's isolate juggling logic. The other crash (#2808) is more of a use-after-free issue. This one should be easier to get to the bottom of.

[liamappelbe]

The only EnterIsolate call in that file is this. That means it's a blocking callback, mayEnterIsolate is true, and the invoking thread is not entered into an isolate. mayEnterIsolate is supposed to be true only if the target isolate is owned by the main thread, and the invoking thread is the main thread. But the assertion failure is saying that the target isolate is already entered by another thread.

Looking at how jni is doing the ownership check, I think it predates the isolate ownership API. package:objective_c does this, but package:jni does this. So I think the simple main thread check it's doing isn't strict enough, and its assumptions are violated in this close/reopen flow. The fix is probably just to migrate jni to the isolate ownership API.

[orestesgaolin]

I understand it may not be easy to answer, and issue tracker may not be a good place to discuss this, but how big of a lift would it be to "migrate JNI to the Ownership API"?

I'm exploring ways to mitigate this crash (e.g., released an alpha version of the app with the current stable Flutter 3.41.4 last night), but I'd love to get a sense of the possible timeline for a fix. Is that something you can share?

[liamappelbe]

It shouldn't be too hard. I've put this at the top of my todo list, and I'll get to it in the next week or so.

[liamappelbe]

@orestesgaolin Are you able to repro the crash yourself? If so I'll send you a commit hash to pin package:jni to, once I've got a candidate fix. If you could verify it fixes the issue that would be very helpful. Otherwise I'm going to have to try to figure out how to repro the issue myself.

[liamappelbe]

@orestesgaolin Actually, the migration was easier than I thought. Here's the candidate fix: #3250. Can you check if this fixes the issue? I think this should pull in the right dep:

dependencies:
  jni:
    git:
      url: git@github.com:dart-lang/native.git
      ref: jnigen_isolate_ownership
      path: pkgs/jni