$ git clone -n https://src.fedoraproject.org/rpms/gravity-beams-and-evaporating-stars.git /var/lib/mock/f40-build-755728-118310/root/chroot_tmpdir/scmroot/gravity-beams-and-evaporating-stars
Cloning into '/var/lib/mock/f40-build-755728-118310/root/chroot_tmpdir/scmroot/gravity-beams-and-evaporating-stars'...
$ git fetch origin ffc579405c0a07f281336e8d37acf862e8fcf55d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gravity-beams-and-evaporating-stars
 * [new ref]         ffc579405c0a07f281336e8d37acf862e8fcf55d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ffc5794 Rebuild for SFML-2.6.1