$ git clone -n https://src.fedoraproject.org/rpms/xgrav.git /var/lib/mock/f45-build-38882-730/root/chroot_tmpdir/scmroot/xgrav
Cloning into '/var/lib/mock/f45-build-38882-730/root/chroot_tmpdir/scmroot/xgrav'...
$ git fetch origin ad6191ca038e20a812bc26a5454035d6b7daf069:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xgrav
 * [new ref]         ad6191ca038e20a812bc26a5454035d6b7daf069 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ad6191c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild