$ git clone -n https://src.fedoraproject.org/rpms/libgrss.git /var/lib/mock/f45-build-16317-485/root/chroot_tmpdir/scmroot/libgrss
Cloning into '/var/lib/mock/f45-build-16317-485/root/chroot_tmpdir/scmroot/libgrss'...
$ git fetch origin d4b845b47446d7e33863e1f0e2426aef68fe9e8d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libgrss
 * [new ref]         d4b845b47446d7e33863e1f0e2426aef68fe9e8d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d4b845b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild