Replying to an old post to add the following:
I fixed this problem, but my issue may have been different than OP’s. I was using git in Cygwin while compiling in Windows. The caching for unix-based and windows-based systems is completely different, so a git status in one was invalidating the cache of the other and forcing it to spend an extra 30s or so doing git status checks. This went away completely when I switched from Cygwin to git bash.
Now it’s lightning fast.