Repository navigation
[flutter_tools] Prevent interactive device selection in machine mode - #188267
Merged
Merged
Conversation
Fixes a crash when running `flutter run --machine` (or other commands in machine mode) when multiple devices are connected and no device is specified. Previously, if multiple devices were connected, the tool would attempt to prompt the user interactively to select a device, even in machine mode. This interactive prompt listens to `stdin` (via a broadcast stream wrapper). Since `stdin` is a single-subscription stream, once it has been listened to by the prompt, it cannot be listened to again. When the machine daemon later attempts to listen to `stdin` to receive JSON-RPC commands, it throws a `StateError: Bad state: Stream has already been listened to.` and crashes. This fix introduces a `canPrompt` flag to device discovery and selection methods (defaulting to `!outputMachineFormat` in `FlutterCommand`), which disables interactive prompting when running in machine mode. Instead, the tool will print the available devices and exit gracefully, which is the correct behavior for machine-to-machine communication when a required parameter is missing. Fixes flutter#175948
bkonyi
marked this pull request as ready for review
June 30, 2026 18:05
Contributor
There was a problem hiding this comment.
Code Review
This pull request introduces a canPrompt parameter to findAllTargetDevices and its helper methods to control interactive device selection prompting, defaulting to false when machine format output is enabled. Unit tests are added to verify these interactions. The reviewer suggested defensively checking if argResults is non-null in outputMachineFormat to prevent potential null pointer errors during early command initialization or in tests.
chingjun
approved these changes
Jun 30, 2026
Contributor
|
autosubmit label was removed for flutter/flutter/188267, because - The status or check suite Google testing has failed. Please fix the issues identified (or deflake) before re-applying this label. |
Contributor
|
autosubmit label was removed for flutter/flutter/188267, because - The status or check suite Google testing has failed. Please fix the issues identified (or deflake) before re-applying this label. |
Contributor
|
autosubmit label was removed for flutter/flutter/188267, because The base commit of the PR is older than 7 days and can not be merged. Please merge the latest changes from the main into this branch and resubmit the PR. |
This was referenced Jul 8, 2026
This was referenced Jul 8, 2026
auto-submit Bot
pushed a commit
to flutter/packages
that referenced
this pull request
Jul 10, 2026
…12169) Manual roll Flutter from 91939cc4db78 to dc2a8703e12b (50 revisions) Manual roll requested by bensonluk@google.com flutter/flutter@91939cc...dc2a870 2026-07-09 chris@bracken.jp [ios,macos] Update swiftc.py flags to match swiftc (flutter/flutter#189174) 2026-07-09 jesswon@google.com [AGP 9] Update Warn Version to AGP 9+ (flutter/flutter#189109) 2026-07-09 154381524+flutteractionsbot@users.noreply.github.com Sync CHANGELOG.md from stable (flutter/flutter#189203) 2026-07-09 mdebbar@google.com [web] Roll Chrome to 145 (framework) (flutter/flutter#182861) 2026-07-09 engine-flutter-autoroll@skia.org Roll Packages from 52d84d6 to 20928d5 (6 revisions) (flutter/flutter#189194) 2026-07-09 zhongliu88889@gmail.com [web] Avoid absolute positioning for base CanvasKit canvas (flutter/flutter#188337) 2026-07-09 engine-flutter-autoroll@skia.org Roll Dart SDK from cdb7217e65aa to a11fb7ed40a5 (6 revisions) (flutter/flutter#189195) 2026-07-09 matt.kosarek@canonical.com Fix dereference of nullptr in the moved-to-rect signal in the Linux embedder (flutter/flutter#189152) 2026-07-09 katelovett@google.com Fix data for design packages (flutter/flutter#189140) 2026-07-09 engine-flutter-autoroll@skia.org Roll Skia from 7b42d1251d54 to ab3a7b98c94d (2 revisions) (flutter/flutter#189181) 2026-07-09 engine-flutter-autoroll@skia.org Roll Skia from 05d9d214e0b7 to 7b42d1251d54 (2 revisions) (flutter/flutter#189175) 2026-07-09 engine-flutter-autoroll@skia.org Roll Skia from 542c8bdd7f4f to 05d9d214e0b7 (4 revisions) (flutter/flutter#189169) 2026-07-09 97480502+b-luk@users.noreply.github.com UberSDF rect handling for thin (line-like) rectangles (flutter/flutter#188821) 2026-07-09 engine-flutter-autoroll@skia.org Roll Skia from dd572c07f63c to 542c8bdd7f4f (4 revisions) (flutter/flutter#189160) 2026-07-09 markzipan@google.com [flutter_tools] Fix hot restart for WASM web builds (flutter/flutter#187898) 2026-07-08 robert.ancell@canonical.com Split FlViewRenderer into OpenGL and software backends (flutter/flutter#188824) 2026-07-08 awolff@google.com Promote android_hardware_smoke_tests out of bringup in CI (flutter/flutter#189081) 2026-07-08 engine-flutter-autoroll@skia.org Roll Skia from 8df24be66531 to dd572c07f63c (4 revisions) (flutter/flutter#189150) 2026-07-08 matt.kosarek@canonical.com Expose LinuxWindowRegistrar on _window_linux.dart in order to better support out of tree LinuxWindowingOwners (flutter/flutter#188917) 2026-07-08 137456488+flutter-pub-roller-bot@users.noreply.github.com Roll pub packages (flutter/flutter#189149) 2026-07-08 codefu@google.com fix(ci): harden some workflows (flutter/flutter#189087) 2026-07-08 engine-flutter-autoroll@skia.org Roll Skia from 51a62da33da0 to 8df24be66531 (1 revision) (flutter/flutter#189139) 2026-07-08 iinozemtsev@google.com Roll Dart SDK to Dart 3.13 beta3 (flutter/flutter#189122) 2026-07-08 digvijaysinghiam@gmail.com [flutter_tools] Don't crash on non-UTF-8 plugin pubspec.yaml (flutter/flutter#188976) 2026-07-08 bkonyi@google.com [flutter_tools] Watch transitive #include headers for FragmentProgram hot reload (flutter/flutter#187945) 2026-07-08 engine-flutter-autoroll@skia.org Roll Skia from 040d9f55de00 to 51a62da33da0 (1 revision) (flutter/flutter#189135) 2026-07-08 engine-flutter-autoroll@skia.org Roll Packages from 92525f5 to 52d84d6 (7 revisions) (flutter/flutter#189134) 2026-07-08 bkonyi@google.com [flutter_tools] Forcefully kill hung subprocesses 5 seconds after timeout (flutter/flutter#187178) 2026-07-08 malo.allee@gmail.com Expose the app's build name and number as compile-time constants (flutter/flutter#187935) 2026-07-08 engine-flutter-autoroll@skia.org Roll Skia from 1ff92f879815 to 040d9f55de00 (1 revision) (flutter/flutter#189131) 2026-07-08 engine-flutter-autoroll@skia.org Roll Skia from 6137414bef5c to 1ff92f879815 (6 revisions) (flutter/flutter#189126) 2026-07-08 brackenavaron@gmail.com [test cross imports] More test/rendering + flutter_test/test fixes (flutter/flutter#188954) 2026-07-08 112751483+shivanshu877@users.noreply.github.com engine: explain why each candidate build was skipped in Flutter web loader (flutter/flutter#186254) 2026-07-08 chris@bracken.jp vscode: add missing unicode.h (flutter/flutter#189102) 2026-07-08 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from 7RjQJBW3m-3Jl-7jr... to QcRFUtvCw2EobfJ8s... (flutter/flutter#189104) 2026-07-08 engine-flutter-autoroll@skia.org Roll Skia from 075fbe4778d9 to 6137414bef5c (10 revisions) (flutter/flutter#189106) 2026-07-08 112751483+shivanshu877@users.noreply.github.com engine: warn on WASM load failure when not crossOriginIsolated (flutter/flutter#186252) 2026-07-08 engine-flutter-autoroll@skia.org Roll Dart SDK from c9bccc09e733 to db2155f56bf3 (2 revisions) (flutter/flutter#189105) 2026-07-08 bkonyi@google.com [flutter_tools] Prevent interactive device selection in machine mode (flutter/flutter#188267) 2026-07-08 bkonyi@google.com [flutter_tools] Fix wireless ADB device discovery when serial contains spaces (flutter/flutter#187943) 2026-07-07 zhongliu88889@gmail.com [web] Fix grouped autofill on iOS Chrome (flutter/flutter#187459) 2026-07-07 rmolivares@renzo-olivares.dev Fix TextSelectionOverlay crash when layout is degenerate (flutter/flutter#188672) 2026-07-07 87962825+kyungilcho@users.noreply.github.com [flutter_tools] Provision Android NDK in the main Gradle invocation (flutter/flutter#186337) 2026-07-07 awolff@google.com Android_hardware_smoke_test: Migrate to AGP 9 (flutter/flutter#189082) ...
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes a crash when running
flutter run --machine(or other commands in machine mode) when multiple devices are connected and no device is specified.Previously, if multiple devices were connected, the tool would attempt to prompt the user interactively to select a device, even in machine mode. This interactive prompt listens to
stdin(via a broadcast stream wrapper). Sincestdinis a single-subscription stream, once it has been listened to by the prompt, it cannot be listened to again. When the machine daemon later attempts to listen tostdinto receive JSON-RPC commands, it throws aStateError: Bad state: Stream has already been listened to.and crashes.This fix introduces a
canPromptflag to device discovery and selection methods (defaulting to!outputMachineFormatinFlutterCommand), which disables interactive prompting when running in machine mode. Instead, the tool will print the available devices and exit gracefully, which is the correct behavior for machine-to-machine communication when a required parameter is missing.Fixes #175948