Assertion failure in ConnectAsync_WithBuffer_Succeeds on Android/MacCatalyst/tvOS (Mono/CoreCLR/NativeAOT)

[MatousBot]

Suggested labels: Known Build Error, test-failure, os-android, os-tvos, os-maccatalyst, arch-x64, arch-x86, arch-arm64, untriaged

Note: This issue was automatically generated by AI-Test-Triage. Please review and triage accordingly.

Build Information

Build: 20260317.4, 20260318.5

Build error leg or test failing: System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds, System.Net.Sockets.Tests.WorkItemExecution

Affected CI jobs: build_Android_x86_Release_AllSubsets_Mono, build_Android_x64_Release_AllSubsets_Mono, build_android_x64_Release_AllSubsets_CoreCLR, build_maccatalyst_arm64_Release_AllSubsets_CoreCLR_Smoke, build_tvos_arm64_Release_AllSubsets_CoreCLR, build_MacCatalyst_x64_Release_AllSubsets_Mono, build_MacCatalyst_arm64_Release_AllSubsets_Mono, build_tvOS_arm64_Release_AllSubsets_Mono, build_android_x64_Release_NativeAOT

Causing Commit Range Information

Commit range: {TODO: Insert commit range or link to changes}

Summary

• xUnit assertion failure (Assert.False) in SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds; not a managed crash or timeout.
• Observed on Android (x86/x64), MacCatalyst and tvOS across Mono, CoreCLR and NativeAOT jobs.
• Failures are isolated single-test flakes in large runs; tests complete quickly (~0.006–0.03s), suggesting flakiness or test logic issue.
• On Android some runs show the test host terminated by SIGKILL and instrumentation/MonoRunner returning non-zero (exit code 1).

Failure Statistics

Note: These statistics are based on the configured time range and might not reflect the full history of the failure.

• Occurrence Count: 28
• First Failure: 2026-03-18 08:02:00 UTC
• Last Failure: 2026-03-19 09:53:20 UTC

Work Items

Showing 10 most recent of 28 occurrences

Work Item	Console Log	Build	Job Name
System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds	View Extract 03-19 04:33:49.479 10403 11037 I DOTNET : Test collection for System.Net.Sockets.Tests.SocketBlockingModeTransitionTests 03-19 04:33:49.507 10403 11037 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 04:33:49.507 10403 11037 I DOTNET : Assert.False() Failure 03-19 04:33:49.507 10403 11037 I DOTNET : Expected: False 03-19 04:33:49.507 10403 11037 I DOTNET : Actual: True 03-19 04:33:49.507 10403 11037 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() 03-19 04:33:49.507 10403 11037 I DOTNET : --- End of stack trace from previous location --- 03-19 04:34:28.670 10403 12486 I DOTNET : Failed tests: 03-19 04:34:28.671 10403 12486 I DOTNET : 1) [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds Test name: System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 04:34:28.671 10403 12486 I DOTNET : Assembly: [System.Net.Sockets.Tests, Version=11.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51] 03-19 04:34:28.671 10403 12486 I DOTNET : Exception messages: Assert.False() Failure 03-19 04:34:28.671 10403 12486 I DOTNET : Expected: False 03-19 04:34:28.671 10403 12486 I DOTNET : Actual: True Exception stack traces: at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() 03-19 04:34:28.671 10403 12486 I DOTNET : --- End of stack trace from previous location --- 03-19 04:34:28.671 10403 12486 I DOTNET : Execution time: 0.0075873 Full Log	20260318.5	build_android_x64_Release_AllSubsets_CoreCLR
System.Net.Sockets.Tests Work Item	View Extract 03-19 04:33:49.471 10403 11037 I DOTNET : [PASS] System.Net.Sockets.Tests.Disconnect_Eap.Disconnect_Success 03-19 04:33:49.479 10403 11037 I DOTNET : Test collection for System.Net.Sockets.Tests.SocketBlockingModeTransitionTests 03-19 04:33:49.507 10403 11037 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 04:33:49.507 10403 11037 I DOTNET : Assert.False() Failure 03-19 04:33:49.507 10403 11037 I DOTNET : Expected: False 03-19 04:33:49.507 10403 11037 I DOTNET : Actual: True 03-19 04:33:49.507 10403 11037 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() ... [04:34:29] info: Found XML result file: '/storage/emulated/0/Android/data/net.dot.System.Net.Sockets.Tests/files/Documents/testResults.xml'(key: test-results-path) [04:34:29] info: Instrumentation finished normally with exit code 1 [04:34:33] fail: Non-success instrumentation exit code: 1, expected: 0 XHarness exit code: 1 (TESTS_FAILED) Full Log	20260318.5	build_android_x64_Release_AllSubsets_CoreCLR
System.Net.Sockets.Tests Work Item	View Extract 03-19 05:12:37.947 4435 4458 I DOTNET : [SKIP] System.Net.Sockets.Tests.AcceptApm.AbortedByDispose_LeaksNoUnobservedExceptions 03-19 05:12:38.361 4435 4458 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 05:12:38.361 4435 4458 I DOTNET : Assert.False() Failure 03-19 05:12:38.361 4435 4458 I DOTNET : Expected: False 03-19 05:12:38.361 4435 4458 I DOTNET : Actual: True 03-19 05:12:38.361 4435 4458 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.<ConnectAsync_WithBuffer_Succeeds>d__10.MoveNext() in /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/Connect.Unix.cs:line 229 03-19 05:12:56.890 4435 4458 I DOTNET : Finished System.Net.Sockets.Tests, Version=11.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51 03-19 05:12:56.891 4435 4458 I DOTNET : Tests run: 2307, Errors: 0, Failures: 1, Skipped: 31. Time: 62.6617444s 03-19 05:12:56.891 4435 4453 I DOTNET : MonoRunner finished, return-code=1 03-19 05:12:57.129 1669 1669 I Zygote : Process 4435 exited due to signal 9 (Killed) [05:13:00] fail: Non-success instrumentation exit code: 1, expected: 0 INSTRUMENTATION_RESULT: return-code=1 INSTRUMENTATION_CODE: 1 Full Log	20260318.5	build_android_x64_Release_NativeAOT
System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds	View Extract 03-19 08:44:01.193 7898 9923 I DOTNET : Test collection for System.Net.Sockets.Tests.SocketBlockingModeTransitionTests 03-19 08:44:01.358 7898 9923 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:44:01.358 7898 9923 I DOTNET : Assert.False() Failure 03-19 08:44:01.358 7898 9923 I DOTNET : Expected: False 03-19 08:44:01.358 7898 9923 I DOTNET : Actual: True 03-19 08:44:01.358 7898 9923 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() 03-19 08:44:01.359 7898 9923 I DOTNET : --- End of stack trace from previous location --- 03-19 08:44:01.401 7898 9923 I DOTNET : [PASS] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.AcceptAsync_AcceptedSocketSyncReceiveWorks ... 03-19 08:44:05.658 1721 1721 E netmgr : Failed to open QEMU pipe 'qemud:network': Invalid argument ... 03-19 08:44:05.928 7898 9994 I DOTNET : Failed tests: 03-19 08:44:05.930 7898 9994 I DOTNET : 1) [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds Test name: System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:44:05.930 7898 9994 I DOTNET : Assembly: [System.Net.Sockets.Tests, Version=11.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51] 03-19 08:44:05.930 7898 9994 I DOTNET : Exception messages: Assert.False() Failure 03-19 08:44:05.930 7898 9994 I DOTNET : Expected: False 03-19 08:44:05.930 7898 9994 I DOTNET : Actual: True Exception stack traces: at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() 03-19 08:44:05.930 7898 9994 I DOTNET : --- End of stack trace from previous location --- 03-19 08:44:05.930 7898 9994 I DOTNET : Execution time: 0.0835186 Full Log	20260318.5	build_Android_x86_Release_AllSubsets_Mono
System.Net.Sockets.Tests Work Item	View Extract 03-19 08:44:01.193 7898 9923 I DOTNET : Test collection for System.Net.Sockets.Tests.SocketBlockingModeTransitionTests 03-19 08:44:01.358 7898 9923 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:44:01.358 7898 9923 I DOTNET : Assert.False() Failure 03-19 08:44:01.358 7898 9923 I DOTNET : Expected: False 03-19 08:44:01.358 7898 9923 I DOTNET : Actual: True 03-19 08:44:01.358 7898 9923 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() ... [08:44:10] fail: Non-success instrumentation exit code: 1, expected: 0 [08:44:10] info: Attempting to remove apk 'net.dot.System.Net.Sockets.Tests'.. [08:44:10] info: Successfully uninstalled net.dot.System.Net.Sockets.Tests [08:44:10] dbug: Saving diagnostics data to '/datadisks/disk1/work/B32E09AB/w/BE910ABB/e/diagnostics.json' XHarness exit code: 1 (TESTS_FAILED) Full Log	20260318.5	build_Android_x86_Release_AllSubsets_Mono
System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds	View Extract 03-19 08:46:21.930 9210 11096 I DOTNET : 03-19 08:46:21.930 9210 11096 I DOTNET : Test collection for System.Net.Sockets.Tests.SocketBlockingModeTransitionTests 03-19 08:46:21.939 9210 11096 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:46:21.939 9210 11096 I DOTNET : Assert.False() Failure 03-19 08:46:21.939 9210 11096 I DOTNET : Expected: False 03-19 08:46:21.939 9210 11096 I DOTNET : Actual: True 03-19 08:46:21.939 9210 11096 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() 03-19 08:46:21.939 9210 11096 I DOTNET : --- End of stack trace from previous location --- 03-19 08:46:21.941 9210 11096 I DOTNET : [PASS] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.AcceptAsync_AcceptedSocketSyncReceiveWorks ... 03-19 08:46:23.504 9210 11191 I DOTNET : Failed tests: 03-19 08:46:23.505 9210 11191 I DOTNET : 1) [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds Test name: System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:46:23.505 9210 11191 I DOTNET : Exception messages: Assert.False() Failure 03-19 08:46:23.505 9210 11191 I DOTNET : Expected: False 03-19 08:46:23.505 9210 11191 I DOTNET : Actual: True 03-19 08:46:23.505 9210 11191 I DOTNET : Execution time: 0.0032081 Full Log	20260318.5	build_Android_x64_Release_AllSubsets_Mono
System.Net.Sockets.Tests Work Item	View Extract 03-19 08:46:21.939 9210 11096 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:46:21.939 9210 11096 I DOTNET : Assert.False() Failure 03-19 08:46:21.939 9210 11096 I DOTNET : Expected: False 03-19 08:46:21.939 9210 11096 I DOTNET : Actual: True 03-19 08:46:21.939 9210 11096 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() ... 03-19 08:46:23.504 9210 11191 I DOTNET : Failed tests: 03-19 08:46:23.505 9210 11191 I DOTNET : 1) [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:46:23.505 9210 11191 I DOTNET : Exception messages: Assert.False() Failure 03-19 08:46:23.505 9210 11191 I DOTNET : Expected: False 03-19 08:46:23.505 9210 11191 I DOTNET : Actual: True [08:46:23] info: Instrumentation finished normally with exit code 1 03-19 08:46:23.603 1670 1670 I Zygote : Process 9210 exited due to signal 9 (Killed) [08:46:27] fail: Non-success instrumentation exit code: 1, expected: 0 [08:46:27] info: Attempting to remove apk 'net.dot.System.Net.Sockets.Tests'.. XHarness exit code: 1 (TESTS_FAILED) Full Log	20260318.5	build_Android_x64_Release_AllSubsets_Mono
System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds	View Extract 03-19 08:54:13.106 9376 11163 I DOTNET : Test collection for System.Net.Sockets.Tests.SocketBlockingModeTransitionTests 03-19 08:54:13.124 9376 11163 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:54:13.124 9376 11163 I DOTNET : Assert.False() Failure 03-19 08:54:13.124 9376 11163 I DOTNET : Expected: False 03-19 08:54:13.124 9376 11163 I DOTNET : Actual: True 03-19 08:54:13.124 9376 11163 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() 03-19 08:54:13.137 9376 11163 I DOTNET : [PASS] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.AcceptAsync_AcceptedSocketSyncReceiveWorks ... 03-19 08:54:23.219 9376 11397 I DOTNET : Failed tests: 03-19 08:54:23.219 9376 11397 I DOTNET : 1) [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds Test name: System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:54:23.219 9376 11397 I DOTNET : Assembly: [System.Net.Sockets.Tests, Version=11.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51] 03-19 08:54:23.219 9376 11397 I DOTNET : Exception messages: Assert.False() Failure 03-19 08:54:23.219 9376 11397 I DOTNET : Execution time: 0.0054965 Full Log	20260318.5	build_android_x64_Release_AllSubsets_CoreCLR
System.Net.Sockets.Tests Work Item	View Extract 03-19 08:54:13.106 9376 11163 I DOTNET : Test collection for System.Net.Sockets.Tests.SocketBlockingModeTransitionTests 03-19 08:54:13.124 9376 11163 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 08:54:13.124 9376 11163 I DOTNET : Assert.False() Failure 03-19 08:54:13.124 9376 11163 I DOTNET : Expected: False 03-19 08:54:13.124 9376 11163 I DOTNET : Actual: True 03-19 08:54:13.124 9376 11163 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds() 03-19 08:54:23.419 1668 1668 I Zygote : Process 9376 exited due to signal 9 (Killed) 03-19 08:54:27] fail: Non-success instrumentation exit code: 1, expected: 0 [08:54:27] info: Attempting to remove apk 'net.dot.System.Net.Sockets.Tests'.. [08:54:28] info: Successfully uninstalled net.dot.System.Net.Sockets.Tests [08:54:28] dbug: Saving diagnostics data to '/datadisks/disk1/work/AB9C090E/w/B61B099E/e/diagnostics.json' XHarness exit code: 1 (TESTS_FAILED) Full Log	20260318.5	build_android_x64_Release_AllSubsets_CoreCLR
System.Net.Sockets.Tests Work Item	View Extract 03-19 09:44:11.937 15284 15307 I DOTNET : [SKIP] System.Net.Sockets.Tests.SocketAsyncEventArgsTest.Connect_Parallel_Fails 03-19 09:44:20.029 15284 15307 I DOTNET : [FAIL] System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds 03-19 09:44:20.029 15284 15307 I DOTNET : Assert.False() Failure 03-19 09:44:20.029 15284 15307 I DOTNET : Expected: False 03-19 09:44:20.029 15284 15307 I DOTNET : Actual: True 03-19 09:44:20.029 15284 15307 I DOTNET : at System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.<ConnectAsync_WithBuffer_Succeeds>d__10.MoveNext() in /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/Connect.Unix.cs:line 229 03-19 09:44:20.923 15284 15307 I DOTNET : [SKIP] System.Net.Sockets.Tests.TelemetryTest.Connect_Success_ActivityRecorded ... 03-19 09:44:29.461 1677 1677 I Zygote : Process 15284 exited due to signal 9 (Killed) 03-19 09:44:30.029 ... INSTRUMENTATION_RESULT: return-code=1 03-19 09:44:30.029 ... INSTRUMENTATION_CODE: 1 [09:44:30] info: Instrumentation finished normally with exit code 1 [09:44:33] info: Wrote current ADB log to /datadisks/disk1/work/A68E0980/w/BC940A18/uploads/adb-logcat-net.dot.System.Net.Sockets.Tests-net.dot.MonoRunner.log [09:44:33] fail: Non-success instrumentation exit code: 1, expected: 0 XHarness exit code: 1 (TESTS_FAILED) Full Log	20260318.5	build_android_x64_Release_NativeAOT

Error Message

{
  "ErrorMessage": "System.Net.Sockets.Tests.SocketBlockingModeTransitionTests.ConnectAsync_WithBuffer_Succeeds",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Report

Build	Definition	Test	Pull Request
1345204	dotnet/runtime	System.Net.Sockets.Tests.NetworkStreamTest.NetworkStream_ReadAsyncTimeout_RemainUseable	#125335
1345062	dotnet/runtime	System.Net.Sockets.Tests.NetworkStreamTest.NetworkStream_ReadAsyncTimeout_RemainUseable	#125793
1345025	dotnet/runtime	System.Net.Sockets.Tests.NetworkStreamTest.NetworkStream_ReadAsyncTimeout_RemainUseable	#125834
1345076	dotnet/runtime	System.Net.Sockets.Tests.WorkItemExecution	#125799
1344976	dotnet/runtime	System.Net.Sockets.Tests.NetworkStreamTest.NetworkStream_ReadAsyncTimeout_RemainUseable	#125519
1344931	dotnet/runtime	System.Net.Sockets.Tests.NetworkStreamTest.NetworkStream_ReadAsyncTimeout_RemainUseable	#124650
1344751	dotnet/runtime	System.Net.Sockets.Tests.NetworkStreamTest.NetworkStream_ReadAsyncTimeout_RemainUseable	#125827
1344659	dotnet/runtime	System.Net.Sockets.Tests.NetworkStreamTest.NetworkStream_ReadAsyncTimeout_RemainUseable	#124266
1344627	dotnet/runtime	System.Net.Sockets.Tests.NetworkStreamTest.NetworkStream_ReadAsyncTimeout_RemainUseable	#125768

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
9	9	9

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