Assert failure: !"OBJECTREF being accessed while thread is in preemptive GC mode."

[VincentBu]

Failed in: runtime-coreclr outerloop 20260805.6

Failed tests:

coreclr browser wasm Checked @ (Ubuntu.2604.Amd64.Open)AzureLinux.3.Amd64.Open@mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-26.04-helix-webassembly-amd64@sha256:0be8725e08b6d0f58ec0290f3f3b70c449123e78b2b33853e9049df84b912fa8
- Loader/ContextualReflection/ContextualReflection/ContextualReflection.cmd
coreclr browser wasm Checked no_tiered_compilation @ (Ubuntu.2604.Amd64.Open)AzureLinux.3.Amd64.Open@mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-26.04-helix-webassembly-amd64@sha256:0be8725e08b6d0f58ec0290f3f3b70c449123e78b2b33853e9049df84b912fa8
- Loader/ContextualReflection/ContextualReflection/ContextualReflection.cmd

Error message:

Out-of-process wrapper failed with exit code 1.
BEGIN EXECUTION
Running with node
CORE_ROOT: /root/helix/work/correlation
ExePath: /root/helix/work/workitem/e/Loader/ContextualReflection/ContextualReflection/ContextualReflection.dll
CLRTestExecutionArguments:
node version: v23.11.1
Timeout in ms: 900000
Running: node --experimental-wasm-exnref --stack-size=8192 /root/helix/work/correlation/corerun.js -c /root/helix/work/correlation -p System.Reflection.Metadata.MetadataUpdater.IsSupported=false -p System.Runtime.Serialization.EnableUnsafeBinaryFormatterSerialization=true /root/helix/work/workitem/e/Loader/ContextualReflection/ContextualReflection/ContextualReflection.dll
ASSERT FAILED
	Expression: !"OBJECTREF being accessed while thread is in preemptive GC mode."
	Location:   /__w/1/s/src/coreclr/vm/object.cpp:514
	Function:   Validate
	Process:    42
Frame (InterpreterFrame): 0x4ff358
   0) Xunit.Assert::GetEqualityComparer, IR_0007
   1) Xunit.Assert::Equal, IR_0010
   2) ContextualReflectionTest.TestResolve::Assert, IR_002e
   3) ContextualReflectionTest.TestResolve::Assert, IR_001c
   4) ContextualReflectionTest.Program::TestResolveMissingAssembly, IR_002f
   5) ContextualReflectionTest.Program::TestAssemblyLoad, IR_0031
   6) ContextualReflectionTest.Program::TestAssemblyLoad, IR_00b8
   7) ContextualReflectionTest.Program::RunTests, IR_0011
   8) ContextualReflectionTest.Program::RunTests, IR_004e
   9) ContextualReflectionTest.Program::TestEntryPoint, IR_0013
  10) __GeneratedMainWrapper::Main, IR_0020
node:internal/process/promises:392
      new UnhandledPromiseRejection(reason);
      ^

UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "Debugger not attached".
    at throwUnhandledRejectionsMode (node:internal/process/promises:392:7)
    at processPromiseRejections (node:internal/process/promises:475:17)
    at process.processTicksAndRejections (node:internal/process/task_queues:106:32) {
  code: 'ERR_UNHANDLED_REJECTION'
}

Node.js v23.11.1
Kill watchdog with PID 674
Expected: 100
Actual: 1
END EXECUTION - FAILED

Stack trace:

   at Xunit.Assert.True(Nullable`1 condition, String userMessage) in /_/src/arcade/src/Microsoft.DotNet.XUnitAssert/src/BooleanAsserts.cs:line 135
   at Xunit.Assert.True(Boolean condition, String userMessage) in /_/src/arcade/src/Microsoft.DotNet.XUnitAssert/src/BooleanAsserts.cs:line 117
   at TestLibrary.OutOfProcessTest.ImportPrecomputedResult(String assemblyPath, String testPathPrefix) in /__w/1/s/src/tests/Common/CoreCLRTestLibrary/OutOfProcessTest.cs:line 285
   at TestLibrary.OutOfProcessTest.RunOutOfProcessTest(String assemblyPath, String testPathPrefix) in /__w/1/s/src/tests/Common/CoreCLRTestLibrary/OutOfProcessTest.cs:line 84
   at Program.<<Main>$>g__TestExecutor389|0_390(StreamWriter tempLogSw, StreamWriter statsCsvSw, StreamWriter outOfProcessPlanWriter, <>c__DisplayClass0_0&)

Known Issue Error Message

DO NOT USE JSON BELOW IF THIS IS A BUILD BREAK otherwise build analysis will allow pull requests to merge that break the build worse. For a build break, do not use this issue form. Make a regular new issue.

Fill the error message using step by step known issues guidance.

{
  "ErrorMessage": [
    "Loader/ContextualReflection/ContextualReflection/ContextualReflection.cmd",
    "OBJECTREF being accessed while thread is in preemptive GC mode."
  ],
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1541935
Error message validated: [Loader/ContextualReflection/ContextualReflection/ContextualReflection.cmd OBJECTREF being accessed while thread is in preemptive GC mode.]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 8/7/2026 1:59:14 PM UTC

Report

Summary

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

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