TimeOutException enabling code coverage with v2

[JuanZamudioGBM]

Hi, I’m trying to upgrade from xUnit v2 to V3 the test that run on our CI/CD and having some problems with code coverage.

With VSTest the command that we use is something like this:
dotnet test --no-restore --no-build --configuration Release --logger "trx;LogFileName=Models.UnitTests.trx" --results-directory src/test-results --settings runsettings_models.xml --collect:"XPlat Code Coverage" src/UnitTests/Models.UnitTests/Models.UnitTests.csproj

The csproj of the test project looks something like this:

<PropertyGroup>
    <TestingPlatformDotnetTestSupport>true</TestingPlatformDotnetTestSupport>
    <UseMicrosoftTestingPlatformRunner>true</UseMicrosoftTestingPlatformRunner>
    <TestingPlatformCaptureOutput>false</TestingPlatformCaptureOutput>
  </PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
    <AllowedReferenceRelatedFileExtensions>.pdb;.xml</AllowedReferenceRelatedFileExtensions>
    <DebugType>pdbonly</DebugType>
    <Optimize>true</Optimize>
  </PropertyGroup>
…
<ItemGroup>
    <PackageReference Include="AwesomeAssertions" Version="9.4.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
    <PackageReference Include="Microsoft.Testing.Extensions.CodeCoverage" Version="18.5.2" />
    <PackageReference Include="Moq" Version="4.20.72" />
    <PackageReference Include="StyleCop.Analyzers" Version="1.2.0-beta.556">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
    <PackageReference Include="xunit.v3.mtp-v2" Version="3.2.2" />
    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
  </ItemGroup>

Running the tests works ok

dotnet run --project src/UnitTests/Models.UnitTests/Models.UnitTests.csproj
xUnit.net v3 Microsoft.Testing.Platform v2 Runner v3.2.2+728c1dce01 (64-bit .NET 10.0.5)


Test run summary: Passed! - src\UnitTests\Models.UnitTests\bin\Debug\net10.0\Models.UnitTests.dll (net10.0|x64)
  total: 15
  failed: 0
  succeeded: 15
  skipped: 0
  duration: 313ms

But adding the flags for code coverage fails with a TimeoutException

dotnet run --project src/UnitTests/.Models.UnitTests/Models.UnitTests.csproj -- --coverage --coverage-output-format cobertura --coverage-output coverage.cobertura.xml --diagnostic --diagnostic-synchronous-write
xUnit.net v3 Microsoft.Testing.Platform v2 Runner v3.2.2+728c1dce01 (64-bit .NET 10.0.5)

Diagnostic file (level 'Trace' with sync flush): [redacted]\Models.UnitTests\bin\Debug\net10.0\TestResults\log_260331022506479.diag
Diagnostic file (level 'Trace' with sync flush): [redacted]\Models.UnitTests\bin\Debug\net10.0\TestResults\log_260331022507230.diag

Unhandled exception. System.TimeoutException: The operation has timed out.
   at System.IO.Pipes.NamedPipeClientStream.ConnectInternal(Int32 timeout, CancellationToken cancellationToken, Int32 startTime)
   at Microsoft.CodeCoverage.Interprocess.LoggerClient.ConnectPipe()
   at Microsoft.CodeCoverage.Interprocess.LoggerClient.SendMessage(Action`1 writerAction)
   at Microsoft.CodeCoverage.Interprocess.LoggerClient.SendGenerateReportsRequestMessage()
   at Microsoft.Testing.Extensions.CodeCoverage.TestingPlatformCoverageDynamicTestSessionLifetimeHandler.OnTestSessionFinishingAsync(ITestSessionContext testSessionContext)
   at Microsoft.Testing.Platform.Hosts.CommonHost.NotifyTestSessionEndAsync(ITestSessionContext testSessionContext, BaseMessageBus baseMessageBus, ServiceProvider serviceProvider, IPlatformOpenTelemetryService otelService) in /_/src/Platform/Microsoft.Testing.Platform/Hosts/CommonTestHost.cs:line 240
   at Microsoft.Testing.Platform.Hosts.CommonHost.ExecuteRequestAsync(ProxyOutputDevice outputDevice, ITestSessionContext testSessionInfo, ServiceProvider serviceProvider, BaseMessageBus baseMessageBus, ITestFramework testFramework, ClientInfo client) in /_/src/Platform/Microsoft.Testing.Platform/Hosts/CommonTestHost.cs:line 171
   at Microsoft.Testing.Platform.Hosts.ConsoleTestHost.InternalRunAsync(CancellationToken cancellationToken) in /_/src/Platform/Microsoft.Testing.Platform/Hosts/ConsoleTestHost.cs:line 85
   at Microsoft.Testing.Platform.Hosts.ConsoleTestHost.InternalRunAsync(CancellationToken cancellationToken) in /_/src/Platform/Microsoft.Testing.Platform/Hosts/ConsoleTestHost.cs:line 117
   at Microsoft.Testing.Platform.Hosts.CommonHost.RunTestAppAsync(IPlatformOpenTelemetryService platformOTelService, CancellationToken testApplicationCancellationToken) in /_/src/Platform/Microsoft.Testing.Platform/Hosts/CommonTestHost.cs:line 130
   at Microsoft.Testing.Platform.Hosts.CommonHost.RunAsync() in /_/src/Platform/Microsoft.Testing.Platform/Hosts/CommonTestHost.cs:line 44
   at Microsoft.Testing.Platform.Hosts.CommonHost.RunAsync() in /_/src/Platform/Microsoft.Testing.Platform/Hosts/CommonTestHost.cs:line 83
   at Microsoft.Testing.Platform.Hosts.TestHostControlledHost.RunAsync() in /_/src/Platform/Microsoft.Testing.Platform/Hosts/TestHostControlledHost.cs:line 24
   at Microsoft.Testing.Platform.Builder.TestApplication.RunAsync() in /_/src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs:line 223
   at Xunit.MicrosoftTestingPlatform.TestPlatformTestFramework.RunAsync(String[] args, Action`2 extensionRegistration) in /_/src/common/MicrosoftTestingPlatform/TestPlatformTestFramework.cs:line 334
   at Models.UnitTests.AutoGenerated.XunitAutoGeneratedEntryPoint.Main(String[] args) in [redacted]Models.UnitTests\obj\Debug\net10.0\XunitAutoGeneratedEntryPoint.cs:line 13

The files end like this

[02:25:16.294 xUnit.net - Information]   Finished:    Models.UnitTests (ID = '66ccf80fed28e7a1a4974fb02f07750ee77b5fd8c4a26a8a28e26187941d6a99')
[02:25:16.304 xUnit.net - Information] === TEST EXECUTION SUMMARY ===
[02:25:16.310 xUnit.net - Information]    Models.UnitTests  Total: 15, Errors: 0, Failed: 0, Skipped: 0, Not Run: 0, Time: 8.355s
2026-03-31T02:25:16.3150593+00:00 Microsoft.Testing.Platform.Messages.AsynchronousMessageBus TRACE The producer '' (ID: TestHostTestFrameworkInvoker) pushed data:
TestRequestExecutionTimeInfo { DisplayName = TestRequestExecutionTimeInfo, Description = Information about the test execution times., TimingInfo = TimingInfo { StartTime = 03/31/2026 2:25:07 AM +00:00, EndTime = 03/31/2026 2:25:16 AM +00:00, Duration = 00:00:08.6870482 } }

[02:25:16.320 TestingPlatformCoverageDynamicTestSessionLifetimeHandler - Information] LoggerClient.SendGenerateReportsRequestMessage: Sending message

[02:25:07.770 TestingPlatformCoverageProcessMonitor - Information] CoveragePipeClient.SendEmptyModuleInstrumentedMessage[0]
[02:25:07.770 TestingPlatformCoverageProcessMonitor - Information] LoggerBase.LoadModuleData[0]: finished Path:C:\Program Files\dotnet\shared\Microsoft.NETCore.App\10.0.5\System.Collections.NonGeneric.dll, time taken: 1
[02:25:07.821 TestingPlatformCoverageProcessMonitor - Information] LoggerBase.LoadModuleData[0]: started Path:[redacted]Models.UnitTests\bin\Debug\net10.0\Models.dll
[02:25:07.822 TestingPlatformCoverageProcessMonitor - Debug] SourceRootTranslator.InternalResolveFilePath: Mapping resolved: '[redacted]Models\obj\Debug\net10.0\Models.pdb' -> '[redacted]Models\obj\Debug\net10.0\.Models.pdb'
[02:25:07.822 TestingPlatformCoverageProcessMonitor - Information] PdbRederProvider.TryFindPdbPath: OriginalLocation, Path:[redacted]Models\obj\Debug\net10.0\Models.pdb, fileExists: True
[02:25:07.841 TestingPlatformCoverageProcessMonitor - Information] MsdiaPdbReaderFactory.GetNativeDataSize for [redacted]Models\obj\Debug\net10.0\Models.pdb returned data size 2320

Any pointers in what I'm doing wrong?

Thanks a lot
Juan Zamudio

[Youssef1313]

Thanks for reporting this @JuanZamudioGBM

• Would you be able to attach a full minimal project that reproduces this?
• Does it make any difference if you try to run with .NET 10 SDK and opt-in to the MTP-based dotnet test via global.json?

Meanwhile, I'm also going to move this issue to Code Coverage repo.

FYI @fhnaseer

[JuanZamudioGBM]

Thanks for reporting this @JuanZamudioGBM

• Would you be able to attach a full minimal project that reproduces this?
• Does it make any difference if you try to run with .NET 10 SDK and opt-in to the MTP-based dotnet test via global.json?

Meanwhile, I'm also going to move this issue to Code Coverage repo.

FYI @fhnaseer

I have this on my global.json but I still get the TimeoutException

"test": {
    "runner": "Microsoft.Testing.Platform"
  }

I'm going to create a repo, but I'm thinking maybe the Antivirus we have running are blocking something.

[JuanZamudioGBM]

This is the repro project

https://github.com/JuanZamudioGBM/repro-coverage-utilities

In my machine fails with this command

dotnet run --project src/UnitTests/Models.NoRef.UnitTests/Models.NoRef.UnitTests.csproj -- --coverage --coverage-output-format cobertura --coverage-output coverage.cobertura.xml

I was also able to get a dump using werFault, the exception is

The thread tried to read from or write to a virtual address for which it does not have the appropriate access.
Unhandled exception at 0x00007FF9AEE6D535 in Models.NoRef.UnitTests.exe.24932.dmp: 0xC0000005: Access violation executing location 0x00007FF9AEE6D535.

The file is less than 70MB if you want it

[fhnaseer]

Thanks for providing the repro. However, I am not able to reproduce this.

Without coverage =>

dotnet run --project .\UnitTests\Models.NoRef.UnitTests\Models.NoRef.UnitTests.csproj
xUnit.net v3 Microsoft.Testing.Platform v2 Runner v3.2.2+728c1dce01 (64-bit .NET 10.0.5)


Test run summary: Passed! - UnitTests\Models.NoRef.UnitTests\bin\Debug\net10.0\Models.NoRef.UnitTests.dll (net10.0|x64)
  total: 15
  failed: 0
  succeeded: 15
  skipped: 0
  duration: 288ms

With coverage =>

dotnet run --project .\UnitTests\Models.NoRef.UnitTests\Models.NoRef.UnitTests.csproj -- --coverage --coverage-output-format cobertura --coverage-output coverage.cobertura.xml --diagnostic --diagnostic-synchronous-write
xUnit.net v3 Microsoft.Testing.Platform v2 Runner v3.2.2+728c1dce01 (64-bit .NET 10.0.5)

Diagnostic file (level 'Trace' with sync flush): D:\devlab\issues\repro-coverage-utilities\src\UnitTests\Models.NoRef.UnitTests\bin\Debug\net10.0\TestResults\log_260401091805873.diag
Diagnostic file (level 'Trace' with sync flush): D:\devlab\issues\repro-coverage-utilities\src\UnitTests\Models.NoRef.UnitTests\bin\Debug\net10.0\TestResults\log_260401091806501.diag


  In process file artifacts produced:
    - UnitTests\Models.NoRef.UnitTests\bin\Debug\net10.0\TestResults\coverage.cobertura.xml

Test run summary: Passed! - UnitTests\Models.NoRef.UnitTests\bin\Debug\net10.0\Models.NoRef.UnitTests.dll (net10.0|x64)
  total: 15
  failed: 0
  succeeded: 15
  skipped: 0
  duration: 824ms

Are you running this on windows?

[JuanZamudioGBM]

Yes windows 11, Version 24H2 (OS Build 26100.8037)

If you can't reproduce it on windows, I'm afraid it's because the exes are being blocked by CrowdStrike or the Defender configuration of our IT department

[fhnaseer]

Can you please try dotnet-coverage collect "dotnet run --project src/UnitTests/Models.NoRef.UnitTests/Models.NoRef.UnitTests.csproj" and see if you get the same issue or not?

https://learn.microsoft.com/en-us/dotnet/core/additional-tools/dotnet-coverage

[JuanZamudioGBM]

This was the result

dotnet-coverage v18.6.2.0 [win-x64 - .NET 8.0.25]

SessionId: 50db2c18-138a-4305-b92c-0ad91079592b
xUnit.net v3 Microsoft.Testing.Platform v2 Runner v3.2.2+728c1dce01 (64-bit .NET 10.0.5)



Test run summary: Passed! - src\UnitTests\Models.NoRef.UnitTests\bin\Debug\net10.0\Models.NoRef.UnitTests.dll (net10.0|x64)
  total: 15
  failed: 0
  succeeded: 15
  skipped: 0
  duration: 481ms

Code coverage results: output.coverage.

After it finished, I run it again with this result:

dotnet-coverage v18.6.2.0 [win-x64 - .NET 8.0.25]

SessionId: 4528c492-c85b-4f65-8e58-274e429e251f
xUnit.net v3 Microsoft.Testing.Platform v2 Runner v3.2.2+728c1dce01 (64-bit .NET 10.0.5)


Test run summary: Passed! - src\UnitTests\Models.NoRef.UnitTests\bin\Debug\net10.0\Models.NoRef.UnitTests.dll (net10.0|x64)
  total: 15
  failed: 0
  succeeded: 15
  skipped: 0
  duration: 11s 624ms

As you can see the second time took more than 11 seconds and didn't get the coverage results.

After the first successful run every time of 6 or 7 runs only one outputs 'Code coverage results: output.coverage.'.

[fhnaseer]

Can you please run it again with log parameters dotnet-coverage collect "dotnet run --project src/UnitTests/Models.NoRef.UnitTests/Models.NoRef.UnitTests.csproj" --log-level Verbose --log-file dc.log

And share logs with us.

[JuanZamudioGBM]

Here are the logs
dc.log
dc_error.log

dc_error.log is the log when it fails

[fhnaseer]

From the logs, it appears that it fails during the instrumentation of C:\Github\repro-coverage-utilities\src\UnitTests\Models.NoRef.UnitTests\bin\Debug\net10.0\Models.dll . Do you see a crash? Can you please create a crash dump and share it?

Also, can you please try running dotnet-coverage instrument C:\Github\repro-coverage-utilities\src\UnitTests\Models.NoRef.UnitTests\bin\Debug\net10.0\Models.dll --log-level Verbose --log-file instr.log and see if you get the following output?

dotnet-coverage v18.6.2.0 [win-x64 - .NET 8.0.25]

Input file successfully instrumented.

You can try it multiple times. For each instrument command, create a copy of original dll and run instrument command on it.

[JuanZamudioGBM]

Here are the logs, one successfull and one when fails

instr_error.log
instr_ok.log

The dumps
https://github.com/JuanZamudioGBM/repro-coverage-utilities/blob/main/Models.NoRef.UnitTests.exe.61188.zip
https://github.com/JuanZamudioGBM/repro-coverage-utilities/blob/main/Models.NoRef.UnitTests.exe.67404.zip

[fhnaseer]

Thanks for the logs and dumps. Can you please also provide dumps of instrument command?

I see there is different data size for instrumentation.

Your instrument command logs
repro-coverage-utilities\src\Code\Models\obj\Debug\net10.0\Models.pdb returned data size 2290

My instrument command logs
repro-coverage-utilities\src\Code\Models\obj\Debug\net10.0\Models.pdb returned data size 2332

Can you please upload dll and pdb as well so that I can try to instrument these and maybe I will be able to reproduce this as well?