$ git clone -n https://src.fedoraproject.org/rpms/crystal-stacker.git /var/lib/mock/f39-build-1536561-36327/root/chroot_tmpdir/scmroot/crystal-stacker
Cloning into '/var/lib/mock/f39-build-1536561-36327/root/chroot_tmpdir/scmroot/crystal-stacker'...
$ git fetch origin a7e78952708f49c0ecab234ff233288775a1a196:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/crystal-stacker
 * [new ref]         a7e78952708f49c0ecab234ff233288775a1a196 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a7e7895 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild