Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1362636
Build error leg or test failing: System.Diagnostics.Tests.ProcessHandlesTests.StandardInput_WithRedirectStandardInput_Throws, System.Diagnostics.Tests.ProcessHandlesTests.StandardHandles_CanSetAndGet, System.Diagnostics.Tests.ProcessHandlesTests.CanImplementPiping, System.Diagnostics.Process.Tests.WorkItemExecution
Pull request: #125441

Affected CI jobs: build_tvos_arm64_Debug_AllSubsets_CoreCLR_Smoke, build_maccatalyst_arm64_Release_AllSubsets_CoreCLR, build_MacCatalyst_x64_Release_AllSubsets_CoreCLR, build_maccatalyst_arm64_Debug_AllSubsets_CoreCLR_Smoke_Debug, build_iossimulator_arm64_Debug_AllSubsets_CoreCLR_Smoke, build_tvos_arm64_Release_AllSubsets_CoreCLR, build_tvos_arm64_Release_AllSubsets_Mono, build_maccatalyst_arm64_Release_AllSubsets_Mono, and others

Error Message

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

{
  "ErrorMessage": ["ProcessHandlesTests", "PlatformNotSupportedException", "System.Diagnostics.Process.Tests"],
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Summary

ProcessHandlesTests and several ProcessTests fail with System.PlatformNotSupportedException on all Apple mobile platforms (iossimulator, maccatalyst, tvos) across CoreCLR, Mono, and NativeAOT runtimes.

The root cause is System.ConsolePal.OpenStandardInputHandle() (and Output/Error variants) throwing PlatformNotSupportedException on iOS/tvOS/MacCatalyst.

Failing tests (14-17 per run):

• ProcessHandlesTests.StandardInput_WithRedirectStandardInput_Throws
• ProcessHandlesTests.StandardHandles_CanSetAndGet
• ProcessHandlesTests.CanImplementPiping
• ProcessHandlesTests.CanRedirectOutputAndErrorToSamePipe
• ProcessHandlesTests.CanRedirectOutputToPipe
• ProcessHandlesTests.CanRedirectToInheritedHandles
• ProcessTests.ProcessStart_TryOpenFolder_UseShellExecuteIsFalse_ThrowsWin32Exception
• ProcessTests.TestStartOnUnixWithBadPermissions
• ProcessTests.TestStartWithBadWorkingDirectory
• And others

Error:

System.PlatformNotSupportedException : Operation is not supported on this platform.
   at System.ConsolePal.OpenStandardInputHandle()
   at System.Diagnostics.Tests.ProcessHandlesTests.StandardInput_WithRedirectStandardInput_Throws()

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1362636
Error message validated: [ProcessHandlesTests PlatformNotSupportedException System.Diagnostics.Process.Tests]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 4/2/2026 10:16:44 AM UTC

Report

Summary