[ci-scan] Test failure: Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass (Windows x86 EventSource)

[radekdoulik]

Description

Windows x86 cDAC GC-reference stress intermittently misses roots in System.RuntimeType.SplitName, GetNestedType, and EventSource initialization. The distinctive signature is cDAC=7 RT=47 frames=12 (match=5 mismatch=7 known_nie=0).

Reproduction Steps

Observed in the runtime-diagnostics pipeline's windows-x86 release CdacStressTest job. The same signature appears in main build 1591981, queued September 11 at commit 3898c7135c4dc861e00f49285d0c275f69e2e6c5, and PR build 1620305. No deterministic local reproduction has been established.

Expected behavior

The cDAC and native runtime report matching GC-reference sets at each stress verification point.

Actual behavior

Seven frames omit roots in the cDAC result. The full failing stack summary is included under Error Details.

Regression?

Pre-existing on main at least since September 11, before PR #135055. Recent main runs also pass this job; the underlying cause has not been identified.

Known Workarounds

None established.

Configuration

Windows x86, Release, cDAC GC-reference stress. The Helix queue uses an x64 Windows host, but the failing runtime/test configuration is x86.

Other information

The signature occurs in BasicAlloc, DeepStack, ExceptionHandling, and NotYetLoadedArgType in build 1620305, and DeepStack, Generics, and CallSignatures in the earlier main build. This issue covers only the EventSource/root-count signature below, not every failure of the stress test or the separate PrestubMethodFrame mismatch in the same PR run.

Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1620305
Build error leg or test failing: windows-x86 release CdacStressTest - Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass
Pull request: #135055

PR failure log: https://helix.dot.net/api/2019-06-17/jobs/eb8ed009-397d-4232-80ff-636980b1e497/workitems/CdacStressTests/console
Main failure log: https://helix.dot.net/api/2019-06-17/jobs/bb870b06-ca01-4182-83b1-870d2b259869/workitems/CdacStressTests/console

KBE authoring guidance (ci-failure-scan)

• Error Details is for readers. Paste the full exception, stack trace, or build error excerpt so the failure is understandable without opening the raw log.
• Build Analysis parses only the single JSON block under Error Message.
• ErrorMessage is a case-sensitive ordinal String.Contains substring copied verbatim from the failing log.
• Set BuildRetry to true only for a clear infrastructure retry case. ExcludeConsoleLog disables Helix console-log scanning.

Error Details

Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass(debuggee: Debuggee { Name = BasicAlloc, WindowsOnly = False, SkipGCRefs = False }) [FAIL]
GCREFS stress test 'BasicAlloc' had 2 failure(s) and 0 known issue(s) out of 4988 verifications.

[FAIL] Thread=0x1970 IP=0x73C1E08C cDAC=7 RT=47 frames=12 (match=5 mismatch=7 known_nie=0)
Stack trace:
  #0 <frame ExternalMethodFrame 0xb7d9c0> (cDAC=1 RT=1)
  #1 <other 0xb7de9c> (cDAC=1 RT=1)
  #2 <other 0xb7e960> (cDAC=3 RT=3)
  #3 <other 0xb7f00c> (cDAC=1 RT=1)
  #4 System.RuntimeType.SplitName(System.String, System.String ByRef, System.String ByRef) (cDAC=0 RT=1) <-- MISMATCH
  #5 System.RuntimeType.GetNestedType(System.String, System.Reflection.BindingFlags) (cDAC=0 RT=3) <-- MISMATCH
  #6 System.Diagnostics.Tracing.EventSource.Initialize(System.Guid, System.String, System.String[]) (cDAC=0 RT=7) <-- MISMATCH
  #7 System.Diagnostics.Tracing.EventSource.DoCommand(System.Diagnostics.Tracing.EventCommandEventArgs) (cDAC=0 RT=4) <-- MISMATCH
  #8 System.Diagnostics.Tracing.EventSource.EnsureDescriptorsInitialized() (cDAC=0 RT=5) <-- MISMATCH
  #9 System.Diagnostics.Tracing.EventSource.InitializeDefaultEventSources() (cDAC=1 RT=1)
  #10 System.Diagnostics.Tracing.EventSource+EventSourceHelpers.CreateManifestAndDescriptors(System.Type, System.String, System.Diagnostics.Tracing.EventSource, System.Diagnostics.Tracing.EventManifestOptions) (cDAC=0 RT=19) <-- MISMATCH
  #11 System.Diagnostics.Tracing.NativeRuntimeEventSource..cctor() (cDAC=0 RT=1) <-- MISMATCH

Error Message

{
  "ErrorMessage": "cDAC=7 RT=47 frames=12 (match=5 mismatch=7 known_nie=0)",
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Agentic workflow metadata (ci-failure-scan)

Workflow artifact: ci-failure-scan
Artifact kind: kbe-verification
Verified match count: 8 hits in failure.log

The exact literal was verified against the failing Helix console; no passing or skipped line matches.

Note

Prepared with GitHub Copilot.

Report

Build	Repository	Test	Pull Request
1622048	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#134813
1622018	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#131907
1621833	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#134813
1621815	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#133890
1621636	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#135044
1621605	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#134813
1621593	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#134966
1621570	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#134494
1621554	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#135068
1621509	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#135067
1621464	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#131907
1621045	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#135093
1621016	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#135010
1620305	dotnet/runtime	Microsoft.Diagnostics.DataContractReader.Tests.GCStress.CdacStressTests.GCRefStress_AllVerificationsPass	#135055

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
2	14	14

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