Managed Code After Thread State Destroyed on .NET 9 and .NET 10

Option 1: Downgrade to .NET 8 (Recommended)

.NET 6.0.36 and .NET 8.0.26 exit cleanly. Downgrade the target framework if clean process exit is required.

Option 2: Use test result files instead of exit codes in CI/CD

The PDF work completes successfully before the assertion fires. Publish test results from result files rather than relying on exit code:

Azure DevOps:

- script: dotnet test --logger "trx" || true
- task: PublishTestResults@2
  inputs:
    testResultsFiles: '**/*.trx'

- script: dotnet test --logger "trx" || true
- task: PublishTestResults@2
  inputs:
    testResultsFiles: '**/*.trx'

GitHub Actions:

- run: dotnet test --logger "trx" || true
- uses: dorny/test-reporter@v1
  with:
    path: '**/*.trx'
    reporter: dotnet-trx

- run: dotnet test --logger "trx" || true
- uses: dorny/test-reporter@v1
  with:
    path: '**/*.trx'
    reporter: dotnet-trx

Option 3: Filter exit code in shell

dotnet run 2>stderr.log; EXIT=$?
if grep -q "thread state has been destroyed" stderr.log; then exit 0; else exit $EXIT; fi

dotnet run 2>stderr.log; EXIT=$?
if grep -q "thread state has been destroyed" stderr.log; then exit 0; else exit $EXIT; fi

Known non-working mitigations: Installation.SkipShutdown = true, SetErrorMode, Environment.Exit(0), and manual GC collection before exit.