dotnet test might clash with tested code that loads Microsoft.Build deps

[JanKrivanek]

Repro

• https://github.com/JanKrivanek/MSBuildStructuredLog/tree/dev/jankrivanek/testgen__0326_003/src/StructuredLogger.Tests
• dotnet test

    C:\Program Files\dotnet\sdk\9.0.202\Microsoft.TestPlatform.targets(48,5): warning : [xUnit.net 00:00:01.78] Skipping: StructuredLogger.Tests (could not find dependent assembly 'Microsoft.Build.Utilities.Core, Version=15.1.0')
    C:\Program Files\dotnet\sdk\9.0.202\Microsoft.TestPlatform.targets(48,5): warning : No test is available in C:\src\binlog-viewer\bin\StructuredLogger.Tests\Debug\net472\StructuredLogger.Tests.dll. Make sure that test discoverer & executors are registered and platform & framework version settings are appropriate and try again.

Test summary: total: 0, failed: 0, succeeded: 0, skipped: 0, duration: 2.8s

Analysis

The tested code loads different version of the binary that the runner complains about

So they probably clash?

E.g. if you'd remove all the rests and keep just https://github.com/JanKrivanek/MSBuildStructuredLog/blob/dev/jankrivanek/testgen__0326_003/src/StructuredLogger.Tests/StructuredLoggerTests.cs - it still fails, untill you remove the TestableStructuredLogger

Blocking?

Luckily not now

[nohwnd]

cloned from your branch, and I don't see it repro. using dotnet sdk 9.0.200

S:\c\MSBuildStructuredLog\src\StructuredLogger.Tests [dev/jankrivanek/testgen__0326_003 ≡ +1 ~0 -0 !]> dotnet test -tl:false

[JanKrivanek]

Sorry for confusion - I did changes on the branche after I created the bug (as I needed to make the tests runnable).

Here is the captured point in time: https://github.com/JanKrivanek/MSBuildStructuredLog/tree/dev/jankrivanek/vstest-failure-demo/src/StructuredLogger.Tests

[nohwnd]

So the version that is mentioned, is the assembly version, which is different than the package version. So we are indeed referencing the correct dll.

The problem is that you don't end up copying it into the output because of PrivateAssets=runtime, and so xunit cannot find it. If you remove PrivateAssets=runtime and add p:DisableMSBuildAssemblyCopyCheck=true to suppress the build check you will see your tests run.

[nohwnd]

(one more caveat you are probably aware of, is that Microsoft.Build* packages restore for multiple TFMs, but the runtime libraries are present only for a specific TFM, so it is easy to update the package version to latest, have it restore, but you won't get the runtime lib into bin. And will get a very similar message to this.

https://github.com/microsoft/vstest/blob/main/eng/Versions.props#L29-L36

[JanKrivanek]

Thank you @nohwnd!