GitLab Admin - Carlos Soriano commented:
It seems very specific to the situation of GIMP i.e. they use CircleCI which is not something we use elsewhere in GNOME, and it can only pull from GitHub. So I think we can help with a tailored solution here i.e. by just cloning somewhere the gimp-macos-build.
Now, I don't see an issue of using GNOME/ if that's just easier... but that could change in the future, whether just staying here in Infrastructure/ and having specific mirroring it's unlikely to change.