@uwestoehr: Can you please test whether the compilation takes still longer with the fix from the PR?
You can apply the fix (temporarily) manually in the packages directory of your Julia installation (sorry, I don’t know where that is located on Windows (just to prove your point from above ;-))).
Alternatively, you can point Julia’s package manager to add https://github.com/PatrickHaecker/PackageCompiler.jl#fix_hang_multiple_threads.