$ git clone -n https://src.fedoraproject.org/rpms/livesys-scripts.git /var/lib/mock/f42-build-side-1-3498656-45963/root/chroot_tmpdir/scmroot/livesys-scripts
Cloning into '/var/lib/mock/f42-build-side-1-3498656-45963/root/chroot_tmpdir/scmroot/livesys-scripts'...
$ git fetch origin c8a20cd41903f2831ab581b0b2f1528673cf9a61:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/livesys-scripts
 * [new ref]         c8a20cd41903f2831ab581b0b2f1528673cf9a61 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c8a20cd Update to 0.8.0