$ git clone -n https://src.fedoraproject.org/rpms/rubygems.git /var/lib/mock/f39-build-1499377-34744/root/chroot_tmpdir/scmroot/rubygems
Cloning into '/var/lib/mock/f39-build-1499377-34744/root/chroot_tmpdir/scmroot/rubygems'...
$ git fetch origin 4ae38aeaca35e3f5b7154d82e67890a6632dbda2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygems
 * [new ref]         4ae38aeaca35e3f5b7154d82e67890a6632dbda2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4ae38ae Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild