$ git clone -n https://src.fedoraproject.org/rpms/snapshot.git /var/lib/mock/f45-build-46410-834/root/chroot_tmpdir/scmroot/snapshot
Cloning into '/var/lib/mock/f45-build-46410-834/root/chroot_tmpdir/scmroot/snapshot'...
$ git fetch origin e942ff6451b194a12ffd6b811f323f0b073a8d04:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/snapshot
 * [new ref]         e942ff6451b194a12ffd6b811f323f0b073a8d04 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e942ff6 Explicitly obsolete cheese