$ git clone -n https://src.fedoraproject.org/rpms/marco.git /var/lib/mock/f40-build-792304-138328/root/chroot_tmpdir/scmroot/marco
Cloning into '/var/lib/mock/f40-build-792304-138328/root/chroot_tmpdir/scmroot/marco'...
$ git fetch origin 6b3f2778017ff8a4d9c6946748c748b324156778:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/marco
 * [new ref]         6b3f2778017ff8a4d9c6946748c748b324156778 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6b3f277 update to 1.28