@scheibelp -- Follow up to #12940

Some of the packages (at least one, but I'm trying to figure out which) point to a private GitHub repo which causes a the command to pause waiting for a username / password. It would be nice if there was a way to skip these...

Steps to reproduce the issue

$ spack mirror create --all

Error Message

Not an error message specifically, but the mirroring will pause waiting for input.