Add Mono Stage 2 Leg to VMR SB

[ellahathaway]

Closes dotnet/source-build#4465

This PR adds a Mono Stage 2 Leg to dotnet-source-build. Here is an example run of the pipeline with the proposed changes (internal Microsoft link).

[mthalman]

I'd like to have dotnet/source-build#4465 triaged before merging this.

[ellahathaway]

I'd like to have dotnet/source-build#4465 triaged before merging this.

Makes sense. I'll convert this to a draft for now.

[MichaelSimons]

@ellahathaway - can you confirm the fsharp fix has flown into the SDK? If not we should hold off on merging.

[ViktorHofer]

Note that CI is currently on the floor. Will be fixed with #41621

[ellahathaway]

@ellahathaway - can you confirm the fsharp fix has flown into the SDK? If not we should hold off on merging.

Sure! Just queued https://dev.azure.com/dnceng/internal/_build/results?buildId=2478624&view=results. If it's green I'll merge.

[ellahathaway]

My test run is encountering the Stage 2 errors described in dotnet/source-build#4477 so I cannot validate if the previous fsharp error was fixed.

[ViktorHofer]

I will try to resolve them on Monday.

[ellahathaway]

I will try to resolve them on Monday.

Thanks Viktor!

[ViktorHofer]

Note that stage2 is still broken until #41826 is merged.

[ellahathaway]

Note that stage2 is still broken until #41826 is merged.

Sounds good. I moved the associated issue to blocked in the meantime.

[ViktorHofer]

This is finally unblocked :)

[ellahathaway]

This is finally unblocked :)

Wonderful! I'll queue a run of the full pipeline to check the stage 2 build.

[ellahathaway]

New pipeline run: https://dev.azure.com/dnceng/internal/_build/results?buildId=2490555&view=results (internal Microsoft link)

[ellahathaway]

More unrelated failures: dotnet/source-build#4494

[ellahathaway]

Testing again now that stage 2 has been fixed: https://dev.azure.com/dnceng/internal/_build/results?buildId=2497104&view=logs&s=9b073b6c-199e-5782-2adb-83c30ea48e21

Edit: Hit dotnet/source-build#4513 so I'm retrying the stage 2 build again.

Edit # 2: It passed on retry! Merging the PR :)