In order to build Arcade in source-build for 7.0, we have to either update the Microsoft.NET.Sdk.WorkloadManifestReader dependency to a 7.0 version or add a reference package to dotnet/source-build-reference-packages for the currently referenced version. Keeping the reference up-to-date (with a dependency flow) seems like the better option and fits well with our future plans. in 7.0 there was a minor API breaking change that needs a code change for - see dotnet/sdk@5d54f73#diff-179f603b4aec1c4ea12b36099ee87cb30dcd74179ed669bca1ca34200fcfb54fR18