Microsoft.CodeAnalysis.VisualBasic.UnitTests.Semantics.BinaryOperators.TestLargeStringConcatenation is flaky

[jasonmalinowski]

It's crashing the test process so we don't get usual logs. Runfo doesn't support making a tracking bug, but you can click here to view impacted builds from the last 24 hours.

[jinujoseph]

cc @allisonchou as tiger

[CyrusNajmabadi]

I hit this here as well: https://dev.azure.com/dnceng/public/_build/results?buildId=1483465&view=logs&j=dba579ed-8e9f-558b-ecaf-aa7fd7f38e7b&t=76ec855e-11f7-53ba-b1cd-457ea9dffea8

[allisonchou]

@vatsalyaagrawal Would it be possible to have this flaky test prioritized? We've been hitting it a lot lately in runs.

[jasonmalinowski]

So this got flakier once we enabled the test dumping support; we're still not entirely sure why. The one belief was that the dump support slowed down the test just a hair, but that may not be the case.

[RikkiGibson]

Is it possible to set this issue up so that runfo starts reporting when this happens?

[jasonmalinowski]

@RikkiGibson I tried. I think there's a long Teams conversation internally about the challenges.

[AlekseyTs]

Do we have a crash dump, or at least a call stack?

[allisonchou]

This might be a partial stack trace (taken from here):

The active test run was aborted. Reason: Test host process crashed
The active Test Run was aborted because the host process exited unexpectedly. Please inspect the call stack above, if available, to get more information about where the exception originated from.
The test running when the crash occurred: 
Microsoft.CodeAnalysis.VisualBasic.UnitTests.Semantics.BinaryOperators.TestLargeStringConcatenation

This test may, or may not be the source of the crash.
Test Run Aborted with error System.Exception: One or more errors occurred.
 ---> System.Exception: Unable to read beyond the end of the stream.
   at System.IO.BinaryReader.Read7BitEncodedInt()
   at System.IO.BinaryReader.ReadString()
   at Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.LengthPrefixCommunicationChannel.NotifyDataAvailable()
   at Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.TcpClientExtensions.MessageLoopAsync(TcpClient client, ICommunicationChannel channel, Action`1 errorHandler, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---.

I'm not seeing anything else unfortunately.