SDK Diff Tests failing with `Didn't find an SDK archive`

[ellahathaway]

Failing build:

/mnt/vss/_work/1/s/Directory.Build.targets(15,5): error : Didn't find an SDK archive. [/mnt/vss/_work/1/s/eng/extract-sdk-archive.proj]Didn't find an SDK archive

This is likely a regression from dotnet/sdk#40983

Link to code change: https://github.com/dotnet/sdk/blame/38e537cdf1cf95c74cd4970862b483dc9b0f774b/src/SourceBuild/content/Directory.Build.targets#L11

[MichaelSimons]

Given the error, it leads me to think this is an issue trying to extract the source-build SDK, not the microsoft built SDK. The VMR's test infrastructure has support for extracting the VMR built SDK here. This is where the exception message is coming from. Try running the tests locally. This logic is new and may have changed since the SDK diff tests last ran.

[ellahathaway]

Looking through the binlogs, you're right that it calls the logic in extract-sdk-archive.proj. This project file depends on the DetermineSourceBuiltSdkVersion, which is where the error occurs. It thinks that the SDKTarballItem is at vmr/artifacts/assets/Release/Sdk and then errors when it can't find the SDK there.