System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle failing in CI

[jakobbotsch]

Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1144025
Build error leg or test failing: System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle
Pull request: #119528

Error Message

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

{
  "ErrorMessage": ["System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle", "Assert.True() Failure", "Expected: True"],
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1144025
Error message validated: [System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle Assert.True() Failure Expected: True]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 9/10/2025 12:16:36 PM UTC

Report

Build	Definition	Test	Pull Request
1340451	dotnet/runtime	System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle	#125706
1338820	dotnet/runtime	System.Diagnostics.Process.Tests.WorkItemExecution	#125643
1338310	dotnet/runtime	System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle
1338029	dotnet/runtime	System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle	#125536
2927142	dotnet-runtime	System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle
1335924	dotnet/runtime	System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle	#125549
2926750	dotnet-runtime	System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle
1334315	dotnet/runtime	System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle	#124770
1333635	dotnet/runtime	System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle	#125416

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
1	9	9

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-diagnostics-process
See info in area-owners.md if you want to be subscribed.

[MihuBot]

I'm a bot. Here are possible related and/or duplicate issues (I may be wrong):

• System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle tests failing #100647
• System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle failing in CI #89842

[adamsitnik]

It's a flaky test that fails once per year (see #100647 and #89842), so for now I am moving it to Future and removing "blocking-clean-ci"

[JulieLeeMSFT]

Failed in:

• runtime-coreclr libraries-jitstressregs 20260315.1

Console Log: Console Log

Failed tests:

- net11.0-windows-Release-x64-jitstressregs3-Windows.10.Amd64.Open
- net11.0-windows-Release-x86-jitstressregs2-Windows.10.Amd64.Open
  - System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle

Error Message:

    System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle(windowStyle: Normal, useShellExecute: True) [FAIL]
      Assert.True() Failure

Stack Trace:

        /_/src/libraries/System.Diagnostics.Process/tests/ProcessStartInfoTests.Windows.cs(118,0): at System.Diagnostics.Tests.ProcessStartInfoTests.TestWindowStyle(ProcessWindowStyle windowStyle, Boolean useShellExecute)
        /_/src/coreclr/System.Private.CoreLib/src/System/Reflection/MethodBaseInvoker.CoreCLR.cs(36,0): at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
        /_/src/libraries/System.Private.CoreLib/src/System/Reflection/MethodBaseInvoker.cs(174,0): at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)