trx file too large with MTP v2

[Coder3333]

I am getting an OutOfMemoryException from TrxResultParser in my AzDO "dotnet test" step with MTP v2. This was never an issue with the same project when I was using VSTest. This particular project has 93 tests. I have other projects with fewer tests that run without issue. Is there something in Microsoft.Testing.Extensions.TrxReport that causes it to produce larger trx files with MTP v2 than with VSTest?

##[error]Error: The process 'F:\agent10\_work\_tool\dotnet8\dotnet.exe' failed with exit code 1
Result Attachments will be stored in LogStore
Run Attachments will be stored in LogStore
Failed to parse result files: System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown.
   at System.Text.StringBuilder.ToString()
   at System.IO.File.ReadAllText(String path, Encoding encoding)
   at Microsoft.TeamFoundation.TestClient.PublishTestResults.TrxResultParser.CreateXmlDocumentFromResultFile(String filePath)
   at Microsoft.TeamFoundation.TestClient.PublishTestResults.TrxResultParser.ParseTestResultFile(TestRunContext runContext, String filePath)
   at Microsoft.TeamFoundation.TestClient.PublishTestResults.TrxResultParser.<>c__DisplayClass1_0.<ParseTestResultFiles>b__0(String file)
   at System.Linq.Enumerable.SelectListIterator`2.MoveNext()
   at System.Linq.Enumerable.WhereEnumerableIterator`1.ToList()
   at Microsoft.TeamFoundation.TestClient.PublishTestResults.TrxResultParser.ParseTestResultFiles(TestRunContext runContext, IList`1 resultFilePaths)
   at Microsoft.VisualStudio.Services.Agent.Worker.TestResults.Parser.ParseFiles(IExecutionContext executionContext, TestRunContext testRunContext, List`1 testResultsFiles, ITestResultParser testResultParser) in D:\a\_work\1\s\src\Agent.Worker\TestResults\Parser.cs:line 57

[Evangelink]

Thanks for taking the time to report the issue @Coder3333, we will look into it asap. We are currently operating at limited capability so there might be some delay.

[Coder3333]

As a workaround, I have configured my logging to write fewer messages to the test output, but it would be nice to understand why this changed between testing platforms.

[Youssef1313]

@Coder3333 Would you be able to look into the TRX files and let us know the differences there? Or attach the two TRX files (one from VSTest and one from MTP) and send to us (can be done privately as well).

[nohwnd]

Youssef look at the linked PR, that I think explains the problem well, it duplicates outputs into every tests, including duplicating the previous output as well. So it grows exponentially.

[Youssef1313]

Let's chat briefly offline.

[MichelZ]

It's related to this then, right? Which is fixed now (unreleased yet):
#7846