Looks like the outerloop is red for a while: https://dev.azure.com/dnceng/public/_build?definitionId=701&_a=summary

example failure:
https://helixre8s23ayyeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-heads-master-09989cbb72234094aa/JIT.Regression/console.86ce84a6.log?sv=2019-07-07&se=2021-02-08T09%3A01%3A25Z&sr=c&sp=rl&sig=nY7VQrL5d%2Bve1Gnjqtw2LOlJHqFLFcibkGpc1NDPy7E%3D

Assertion failed '(varDsc->lvType != TYP_UNDEF) && (varDsc->lvType != TYP_VOID) && (varDsc->lvType != TYP_UNKNOWN)' in 'FullProof:Test():int' during 'Mark local vars' (IL size 1446)

I can look at it next week but if somebody wants to get a crossgen2 debugging experience feel free to take, @dotnet/jit-contrib