SourceFileUpdateTests.RenameSourceFile: intermittent hang (test host hang-dump timeout, exit code 7)

[MichaelSimons]

Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1527013
Leg Name: TestBuild: windows (x64) - windows.amd64.vs2026.pre.scout.open — Helix work item dotnet-watch.Tests.dll.7
Helix job: 43a7784c-9825-458f-8498-3a51cc5a9004
Pull request where encountered: #55458 (failed on a manual-retry run; the same suite passed on retry in build 1527662)

Summary

Microsoft.DotNet.Watch.UnitTests.SourceFileUpdateTests.RenameSourceFile (the useMove: false variant) intermittently hangs. When the blame hang-dump timeout of 00:48:00 fires, RenameSourceFile (False) is reported as still running; hang dumps are collected for the dotnet / WatchNoDepsApp process tree, the test host is killed, and the Helix work item finishes with exit code 7, failing the Monitor Helix Jobs step and turning the whole build red. The failure is intermittent (passed on retry), so it is tracked with BuildRetry: true.

This is the hang variant of RenameSourceFile, distinct from the assertion-failure variant tracked by #55137 (failed RenameSourceFile … FileNotFoundException on Foo.cs, exit code 2). Because the two failure modes surface with different console output and different exit codes, they are tracked separately with mode-specific patterns to avoid cross-matching — consistent with how the sibling hangs #55258 (LoggingTests.BinaryLogs) and #55430 (MobileHotReloadTests.HotReload_WithWebSocketCapability) are tracked. Likely related to the open hot-reload startup hang product bug #53289.

Error Details

dotnet watch ?? Build failed: C:\h\w\9CC80899\t\dotnetSdkTests\...\WatchNoDepsApp.csproj
Hang dump timeout of '00:48:00' expired
The following tests were still running when dump was taken (format: [<time-elapsed-since-start>] <name>):
[00:49:46] RenameSourceFile (False)
Creating dump file 'C:\h\w\9CC80899\w\AFCA0975\e\dotnet_5804_hang.dmp'
...
Test host crashed; recovered 27 test result(s) from the TRX streaming sidecar (additional results that were in flight at crash time may be missing).
Test application process didn't exit gracefully, exit code is '-1'
set _commandExitCode=7
EXIT /b 7
['dotnet-watch.Tests.dll.7' END OF WORK ITEM LOG: Command exited with 7]

AzDO reported:

Work item 'dotnet-watch.Tests.dll.7' in job 'Windows x64 - windows.amd64.vs2026.pre.scout.open' failed (Finished, exit code 7).

Error Message

{
    "ErrorMessage": [
        "Hang dump timeout of",
        "] RenameSourceFile",
        "END OF WORK ITEM LOG: Command exited with 7"
    ],
    "BuildRetry": true,
    "ExcludeConsoleLog": false
}

The multi-line pattern is intentionally shard-agnostic (it does not pin the .dll.7 shard number). It requires, in order: the blame hang-dump timeout message, RenameSourceFile reported as still-running when the dump was taken, and the work item exiting with code 7. Because the assertion-failure variant (#55137) produces a failed RenameSourceFile line and exits with code 2 — never emitting the Hang dump timeout of / END OF WORK ITEM LOG: Command exited with 7 lines — this hang pattern does not cross-match #55137. Validated with Test-KnownIssuePattern.ps1 against the failing work item console log (RESULT: PASS).

ExcludeConsoleLog is false because these lines appear only in the Helix work-item console log, not the AzDO build log.

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1527013
Error message validated: [Hang dump timeout of ] RenameSourceFile END OF WORK ITEM LOG: Command exited with 7]
Result validation: ❌ Known issue did not match with the provided build.
Validation performed at: 7/27/2026 12:59:46 PM UTC

Report

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
0	0	0