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[flutter_tools] Fix unhandled DebugAdapterException on early process termination - #192294
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…termination When a target process exits before debugger initialization completes, the debug adapter previously threw an unhandled DebugAdapterException in _handleAppStarted because isTerminating was not yet true when the debuggerInitializationFailedCompleter error was handled. This change: 1. Sets isTerminating to true immediately in FlutterBaseDebugAdapter.handleSessionTerminate. 2. Catches DebugAdapterException in FlutterDebugAdapter._handleAppStarted, outputting the error message to the console and cleanly returning without rethrowing. 3. Formats the early termination message cleanly when exitSuffix is provided. 4. Adds regression tests verifying early process exit does not produce unhandled exceptions in launch and attach modes.
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Code Review
This pull request updates the Flutter debug adapters to handle cases where the process terminates before the debugger is initialized, preventing unhandled exceptions. It catches DebugAdapterException to output the error message to the console and adds corresponding tests. The review feedback notes that catching all other exceptions on Object and printing them to the console when isTerminating is false silently swallows unexpected errors, and suggests preserving the original rethrow behavior for non-DebugAdapterException exceptions.
| } on Object catch (e) { | ||
| if (!isTerminating) { | ||
| rethrow; | ||
| sendConsoleOutput('Failed to initialize debugger: $e'); | ||
| } | ||
| return; |
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The PR description states that the goal is to catch DebugAdapterException and send it to console output rather than rethrowing. However, the current implementation also changes the behavior for other unexpected exceptions (caught via on Object catch (e)) when isTerminating is false, by printing them to the console and returning instead of rethrowing them.
To ensure unexpected programming errors or other critical failures are still reported and not silently swallowed, we should preserve the original rethrow behavior for non-DebugAdapterException exceptions when isTerminating is false.
| } on Object catch (e) { | |
| if (!isTerminating) { | |
| rethrow; | |
| sendConsoleOutput('Failed to initialize debugger: $e'); | |
| } | |
| return; | |
| } on Object catch (e) { | |
| if (!isTerminating) { | |
| rethrow; | |
| } | |
| return; |
…12760) Manual roll Flutter from 70797e15325e to 5a6cfa7f3d26 (52 revisions) Manual roll requested by bensonluk@google.com flutter/flutter@70797e1...5a6cfa7 2026-09-04 bkonyi@google.com [tool] Migrate ScreenshotCommand to modular dependency injection (flutter/flutter#190767) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from 8fce167bdded to 93ac1e630d1d (3 revisions) (flutter/flutter#192306) 2026-09-04 okorohelijah@google.com Add iOS Universal Link integration test (Simulator) (flutter/flutter#191443) 2026-09-04 269567208+reidbaker-agent@users.noreply.github.com [AGP 9.1.0 Migration #5] Delete getLegacyAndroidExtension and migrate NDK fallback to public DSL (flutter/flutter#192116) 2026-09-04 bkonyi@google.com Reland "[tool_tests] Remove bringup from Windows tool_tests_commands_2_2" (#191732) (flutter/flutter#191802) 2026-09-04 bkonyi@google.com [flutter_tools] Fix unhandled DebugAdapterException on early process termination (flutter/flutter#192294) 2026-09-04 engine-flutter-autoroll@skia.org Roll Packages from f9b3954 to 9af9c60 (4 revisions) (flutter/flutter#192292) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from 2e3f7e07eee6 to 8fce167bdded (5 revisions) (flutter/flutter#192283) 2026-09-04 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from GTZNkoIR_WegRPWgL... to FgDQeF6jb1dVRVh3K... (flutter/flutter#192276) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from b6b00df360e5 to 2e3f7e07eee6 (2 revisions) (flutter/flutter#192275) 2026-09-04 cetinibrahim.ci@gmail.com [iOS] TextField should support typing accented words with external keyboard (flutter/flutter#191062) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from 1f68c0b16f17 to b6b00df360e5 (7 revisions) (flutter/flutter#192269) 2026-09-04 kevmoo@users.noreply.github.com [flutter_tools] add typed enum and defaulted option descriptors (flutter/flutter#191760) 2026-09-04 engine-flutter-autoroll@skia.org Roll Dart SDK from c2edc382a4f8 to 5501d02b583d (1 revision) (flutter/flutter#192263) 2026-09-04 robert.ancell@canonical.com [Linux] Use fences to synchronize frames between OpenGL contexts (flutter/flutter#192098) 2026-09-03 brunocorona.alcantar@gmail.com Defer semantics geometry updates for blocked branches (flutter/flutter#192146) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 8d3e197531c6 to 1f68c0b16f17 (8 revisions) (flutter/flutter#192244) 2026-09-03 57765714+Vi-debug@users.noreply.github.com Fix DeleteSurrounding splitting UTF-16 surrogate pairs (flutter/flutter#190514) 2026-09-03 32538273+ValentinVignal@users.noreply.github.com Remove no-shuffle from progress indicator test (flutter/flutter#186655) 2026-09-03 srawlins@google.com [material] Remove unused parameters from constructors of generic test class (flutter/flutter#191764) 2026-09-03 97480502+b-luk@users.noreply.github.com Handle linear and radial gradients in UberSDF (re-implement after fix) (flutter/flutter#192124) 2026-09-03 engine-flutter-autoroll@skia.org Roll Dart SDK from fcbfb64f42a1 to c2edc382a4f8 (2 revisions) (flutter/flutter#192240) 2026-09-03 34871572+gmackall@users.noreply.github.com Fix parsing of --enable-hcpp-and-surface-control switch and add --no-enable-hcpp tests (flutter/flutter#192202) 2026-09-03 97480502+b-luk@users.noreply.github.com Fix issue where shapes rendered with gradient+blur+rotation end up incorrectly cut off (flutter/flutter#192136) 2026-09-03 47866232+chunhtai@users.noreply.github.com Fix sibling nodes crash under MergeSemantics (flutter/flutter#191587) 2026-09-03 30870216+gaaclarke@users.noreply.github.com Makes backdrop groups operate on the union. (flutter/flutter#191838) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 008936396810 to 8d3e197531c6 (1 revision) (flutter/flutter#192236) 2026-09-03 parlough@gmail.com [docs] Remove superseded AI rules for Flutter (flutter/flutter#192185) 2026-09-03 15619084+vashworth@users.noreply.github.com Collect analytics about SwiftPM errors and warnings (flutter/flutter#191746) 2026-09-03 engine-flutter-autoroll@skia.org Roll Packages from 18fe786 to f9b3954 (7 revisions) (flutter/flutter#192235) 2026-09-03 robert.ancell@canonical.com [Linux] Remove frame sharing between OpenGL contexts (flutter/flutter#192150) 2026-09-03 engine-flutter-autoroll@skia.org Roll Dart SDK from cf79067a1e44 to fcbfb64f42a1 (1 revision) (flutter/flutter#192228) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 731fe9af4c0b to 008936396810 (3 revisions) (flutter/flutter#192225) 2026-09-03 engine-flutter-autoroll@skia.org Roll Dart SDK from 700ab60bfe53 to cf79067a1e44 (2 revisions) (flutter/flutter#192219) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 823f82e18177 to 731fe9af4c0b (5 revisions) (flutter/flutter#192217) 2026-09-03 louisehsu@google.com Fixes OverlayPortal semantics bounds corruption (flutter/flutter#192139) 2026-09-03 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from idslm9FikVLy2K_A-... to GTZNkoIR_WegRPWgL... (flutter/flutter#192215) 2026-09-03 engine-flutter-autoroll@skia.org Roll Fuchsia Test Scripts from u_fSMsPU22VvUsvSo... to VObjlh3xw2P9sEbC_... (flutter/flutter#192212) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from ae22da2e8308 to 823f82e18177 (13 revisions) (flutter/flutter#192209) 2026-09-02 ishaquehassan@gmail.com Expose skipTraversal in FocusableActionDetector (flutter/flutter#191308) 2026-09-02 97480502+b-luk@users.noreply.github.com Add `IsProgram` mock method to `MockGLESImpl`, use it in `BufferBindingsGLESTest` (flutter/flutter#192196) 2026-09-02 uros.radulovic23@gmail.com Fix nested scroll view fling crash (flutter/flutter#191130) 2026-09-02 brunocorona.alcantar@gmail.com Fix TabBarView/PageView edge auto-scroll during mouse text selection (flutter/flutter#189544) 2026-09-02 30870216+gaaclarke@users.noreply.github.com Bypass gamma correction when alpha >= 1.0 (flutter/flutter#192193) ...
…lutter#12760) Manual roll Flutter from 70797e15325e to 5a6cfa7f3d26 (52 revisions) Manual roll requested by bensonluk@google.com flutter/flutter@70797e1...5a6cfa7 2026-09-04 bkonyi@google.com [tool] Migrate ScreenshotCommand to modular dependency injection (flutter/flutter#190767) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from 8fce167bdded to 93ac1e630d1d (3 revisions) (flutter/flutter#192306) 2026-09-04 okorohelijah@google.com Add iOS Universal Link integration test (Simulator) (flutter/flutter#191443) 2026-09-04 269567208+reidbaker-agent@users.noreply.github.com [AGP 9.1.0 Migration flutter#5] Delete getLegacyAndroidExtension and migrate NDK fallback to public DSL (flutter/flutter#192116) 2026-09-04 bkonyi@google.com Reland "[tool_tests] Remove bringup from Windows tool_tests_commands_2_2" (#191732) (flutter/flutter#191802) 2026-09-04 bkonyi@google.com [flutter_tools] Fix unhandled DebugAdapterException on early process termination (flutter/flutter#192294) 2026-09-04 engine-flutter-autoroll@skia.org Roll Packages from f9b3954 to 9af9c60 (4 revisions) (flutter/flutter#192292) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from 2e3f7e07eee6 to 8fce167bdded (5 revisions) (flutter/flutter#192283) 2026-09-04 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from GTZNkoIR_WegRPWgL... to FgDQeF6jb1dVRVh3K... (flutter/flutter#192276) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from b6b00df360e5 to 2e3f7e07eee6 (2 revisions) (flutter/flutter#192275) 2026-09-04 cetinibrahim.ci@gmail.com [iOS] TextField should support typing accented words with external keyboard (flutter/flutter#191062) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from 1f68c0b16f17 to b6b00df360e5 (7 revisions) (flutter/flutter#192269) 2026-09-04 kevmoo@users.noreply.github.com [flutter_tools] add typed enum and defaulted option descriptors (flutter/flutter#191760) 2026-09-04 engine-flutter-autoroll@skia.org Roll Dart SDK from c2edc382a4f8 to 5501d02b583d (1 revision) (flutter/flutter#192263) 2026-09-04 robert.ancell@canonical.com [Linux] Use fences to synchronize frames between OpenGL contexts (flutter/flutter#192098) 2026-09-03 brunocorona.alcantar@gmail.com Defer semantics geometry updates for blocked branches (flutter/flutter#192146) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 8d3e197531c6 to 1f68c0b16f17 (8 revisions) (flutter/flutter#192244) 2026-09-03 57765714+Vi-debug@users.noreply.github.com Fix DeleteSurrounding splitting UTF-16 surrogate pairs (flutter/flutter#190514) 2026-09-03 32538273+ValentinVignal@users.noreply.github.com Remove no-shuffle from progress indicator test (flutter/flutter#186655) 2026-09-03 srawlins@google.com [material] Remove unused parameters from constructors of generic test class (flutter/flutter#191764) 2026-09-03 97480502+b-luk@users.noreply.github.com Handle linear and radial gradients in UberSDF (re-implement after fix) (flutter/flutter#192124) 2026-09-03 engine-flutter-autoroll@skia.org Roll Dart SDK from fcbfb64f42a1 to c2edc382a4f8 (2 revisions) (flutter/flutter#192240) 2026-09-03 34871572+gmackall@users.noreply.github.com Fix parsing of --enable-hcpp-and-surface-control switch and add --no-enable-hcpp tests (flutter/flutter#192202) 2026-09-03 97480502+b-luk@users.noreply.github.com Fix issue where shapes rendered with gradient+blur+rotation end up incorrectly cut off (flutter/flutter#192136) 2026-09-03 47866232+chunhtai@users.noreply.github.com Fix sibling nodes crash under MergeSemantics (flutter/flutter#191587) 2026-09-03 30870216+gaaclarke@users.noreply.github.com Makes backdrop groups operate on the union. (flutter/flutter#191838) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 008936396810 to 8d3e197531c6 (1 revision) (flutter/flutter#192236) 2026-09-03 parlough@gmail.com [docs] Remove superseded AI rules for Flutter (flutter/flutter#192185) 2026-09-03 15619084+vashworth@users.noreply.github.com Collect analytics about SwiftPM errors and warnings (flutter/flutter#191746) 2026-09-03 engine-flutter-autoroll@skia.org Roll Packages from 18fe786 to f9b3954 (7 revisions) (flutter/flutter#192235) 2026-09-03 robert.ancell@canonical.com [Linux] Remove frame sharing between OpenGL contexts (flutter/flutter#192150) 2026-09-03 engine-flutter-autoroll@skia.org Roll Dart SDK from cf79067a1e44 to fcbfb64f42a1 (1 revision) (flutter/flutter#192228) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 731fe9af4c0b to 008936396810 (3 revisions) (flutter/flutter#192225) 2026-09-03 engine-flutter-autoroll@skia.org Roll Dart SDK from 700ab60bfe53 to cf79067a1e44 (2 revisions) (flutter/flutter#192219) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 823f82e18177 to 731fe9af4c0b (5 revisions) (flutter/flutter#192217) 2026-09-03 louisehsu@google.com Fixes OverlayPortal semantics bounds corruption (flutter/flutter#192139) 2026-09-03 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from idslm9FikVLy2K_A-... to GTZNkoIR_WegRPWgL... (flutter/flutter#192215) 2026-09-03 engine-flutter-autoroll@skia.org Roll Fuchsia Test Scripts from u_fSMsPU22VvUsvSo... to VObjlh3xw2P9sEbC_... (flutter/flutter#192212) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from ae22da2e8308 to 823f82e18177 (13 revisions) (flutter/flutter#192209) 2026-09-02 ishaquehassan@gmail.com Expose skipTraversal in FocusableActionDetector (flutter/flutter#191308) 2026-09-02 97480502+b-luk@users.noreply.github.com Add `IsProgram` mock method to `MockGLESImpl`, use it in `BufferBindingsGLESTest` (flutter/flutter#192196) 2026-09-02 uros.radulovic23@gmail.com Fix nested scroll view fling crash (flutter/flutter#191130) 2026-09-02 brunocorona.alcantar@gmail.com Fix TabBarView/PageView edge auto-scroll during mouse text selection (flutter/flutter#189544) 2026-09-02 30870216+gaaclarke@users.noreply.github.com Bypass gamma correction when alpha >= 1.0 (flutter/flutter#192193) ...
…lutter#12760) Manual roll Flutter from 70797e15325e to 5a6cfa7f3d26 (52 revisions) Manual roll requested by bensonluk@google.com flutter/flutter@70797e1...5a6cfa7 2026-09-04 bkonyi@google.com [tool] Migrate ScreenshotCommand to modular dependency injection (flutter/flutter#190767) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from 8fce167bdded to 93ac1e630d1d (3 revisions) (flutter/flutter#192306) 2026-09-04 okorohelijah@google.com Add iOS Universal Link integration test (Simulator) (flutter/flutter#191443) 2026-09-04 269567208+reidbaker-agent@users.noreply.github.com [AGP 9.1.0 Migration flutter#5] Delete getLegacyAndroidExtension and migrate NDK fallback to public DSL (flutter/flutter#192116) 2026-09-04 bkonyi@google.com Reland "[tool_tests] Remove bringup from Windows tool_tests_commands_2_2" (#191732) (flutter/flutter#191802) 2026-09-04 bkonyi@google.com [flutter_tools] Fix unhandled DebugAdapterException on early process termination (flutter/flutter#192294) 2026-09-04 engine-flutter-autoroll@skia.org Roll Packages from f9b3954 to 9af9c60 (4 revisions) (flutter/flutter#192292) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from 2e3f7e07eee6 to 8fce167bdded (5 revisions) (flutter/flutter#192283) 2026-09-04 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from GTZNkoIR_WegRPWgL... to FgDQeF6jb1dVRVh3K... (flutter/flutter#192276) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from b6b00df360e5 to 2e3f7e07eee6 (2 revisions) (flutter/flutter#192275) 2026-09-04 cetinibrahim.ci@gmail.com [iOS] TextField should support typing accented words with external keyboard (flutter/flutter#191062) 2026-09-04 engine-flutter-autoroll@skia.org Roll Skia from 1f68c0b16f17 to b6b00df360e5 (7 revisions) (flutter/flutter#192269) 2026-09-04 kevmoo@users.noreply.github.com [flutter_tools] add typed enum and defaulted option descriptors (flutter/flutter#191760) 2026-09-04 engine-flutter-autoroll@skia.org Roll Dart SDK from c2edc382a4f8 to 5501d02b583d (1 revision) (flutter/flutter#192263) 2026-09-04 robert.ancell@canonical.com [Linux] Use fences to synchronize frames between OpenGL contexts (flutter/flutter#192098) 2026-09-03 brunocorona.alcantar@gmail.com Defer semantics geometry updates for blocked branches (flutter/flutter#192146) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 8d3e197531c6 to 1f68c0b16f17 (8 revisions) (flutter/flutter#192244) 2026-09-03 57765714+Vi-debug@users.noreply.github.com Fix DeleteSurrounding splitting UTF-16 surrogate pairs (flutter/flutter#190514) 2026-09-03 32538273+ValentinVignal@users.noreply.github.com Remove no-shuffle from progress indicator test (flutter/flutter#186655) 2026-09-03 srawlins@google.com [material] Remove unused parameters from constructors of generic test class (flutter/flutter#191764) 2026-09-03 97480502+b-luk@users.noreply.github.com Handle linear and radial gradients in UberSDF (re-implement after fix) (flutter/flutter#192124) 2026-09-03 engine-flutter-autoroll@skia.org Roll Dart SDK from fcbfb64f42a1 to c2edc382a4f8 (2 revisions) (flutter/flutter#192240) 2026-09-03 34871572+gmackall@users.noreply.github.com Fix parsing of --enable-hcpp-and-surface-control switch and add --no-enable-hcpp tests (flutter/flutter#192202) 2026-09-03 97480502+b-luk@users.noreply.github.com Fix issue where shapes rendered with gradient+blur+rotation end up incorrectly cut off (flutter/flutter#192136) 2026-09-03 47866232+chunhtai@users.noreply.github.com Fix sibling nodes crash under MergeSemantics (flutter/flutter#191587) 2026-09-03 30870216+gaaclarke@users.noreply.github.com Makes backdrop groups operate on the union. (flutter/flutter#191838) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 008936396810 to 8d3e197531c6 (1 revision) (flutter/flutter#192236) 2026-09-03 parlough@gmail.com [docs] Remove superseded AI rules for Flutter (flutter/flutter#192185) 2026-09-03 15619084+vashworth@users.noreply.github.com Collect analytics about SwiftPM errors and warnings (flutter/flutter#191746) 2026-09-03 engine-flutter-autoroll@skia.org Roll Packages from 18fe786 to f9b3954 (7 revisions) (flutter/flutter#192235) 2026-09-03 robert.ancell@canonical.com [Linux] Remove frame sharing between OpenGL contexts (flutter/flutter#192150) 2026-09-03 engine-flutter-autoroll@skia.org Roll Dart SDK from cf79067a1e44 to fcbfb64f42a1 (1 revision) (flutter/flutter#192228) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 731fe9af4c0b to 008936396810 (3 revisions) (flutter/flutter#192225) 2026-09-03 engine-flutter-autoroll@skia.org Roll Dart SDK from 700ab60bfe53 to cf79067a1e44 (2 revisions) (flutter/flutter#192219) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from 823f82e18177 to 731fe9af4c0b (5 revisions) (flutter/flutter#192217) 2026-09-03 louisehsu@google.com Fixes OverlayPortal semantics bounds corruption (flutter/flutter#192139) 2026-09-03 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from idslm9FikVLy2K_A-... to GTZNkoIR_WegRPWgL... (flutter/flutter#192215) 2026-09-03 engine-flutter-autoroll@skia.org Roll Fuchsia Test Scripts from u_fSMsPU22VvUsvSo... to VObjlh3xw2P9sEbC_... (flutter/flutter#192212) 2026-09-03 engine-flutter-autoroll@skia.org Roll Skia from ae22da2e8308 to 823f82e18177 (13 revisions) (flutter/flutter#192209) 2026-09-02 ishaquehassan@gmail.com Expose skipTraversal in FocusableActionDetector (flutter/flutter#191308) 2026-09-02 97480502+b-luk@users.noreply.github.com Add `IsProgram` mock method to `MockGLESImpl`, use it in `BufferBindingsGLESTest` (flutter/flutter#192196) 2026-09-02 uros.radulovic23@gmail.com Fix nested scroll view fling crash (flutter/flutter#191130) 2026-09-02 brunocorona.alcantar@gmail.com Fix TabBarView/PageView edge auto-scroll during mouse text selection (flutter/flutter#189544) 2026-09-02 30870216+gaaclarke@users.noreply.github.com Bypass gamma correction when alpha >= 1.0 (flutter/flutter#192193) ...
Description
When a target application process exits prematurely (e.g. exit code 255) before the Debug Adapter Protocol (DAP) initialization handshake completes,
flutter_toolscrashed with an unhandledDebugAdapterExceptionin the Dart Zone.In Flutter 3.47.2 telemetry, this was the #3 top crasher with 203 crashes (
DebugAdapterException-34d39b25).Root Cause
FlutterBaseDebugAdapter.handleSessionTerminatecompleteddebuggerInitializationFailedCompleter.completeError(...)before callingsuper.handleSessionTerminate(...).package:dap_adapters(DartDebugAdapter),handleSessionTerminateis asynchronous and awaits pending output events before settingisTerminating = true.FlutterDebugAdapter._handleAppStarted, the unawaited asynchronous message handler caught the error whileisTerminatingwas stillfalse, rethrowingDebugAdapterExceptioninto the Zone.Fix
isTerminating = trueinFlutterBaseDebugAdapter.handleSessionTerminate.FlutterDebugAdapter._handleAppStarted, catchDebugAdapterExceptionand send the message to console output rather than rethrowing into the Zone.exitSuffixis provided.Related Issues
DebugAdapterException-34d39b25in Flutter 3.47.1 and 3.47.2 telemetry.Tests
packages/flutter_tools/test/general.shard/dap/flutter_adapter_test.dartandflutter_test_adapter_test.dartverifying that early process exit outputs cleanly to console and does not produce unhandled asynchronous exceptions.