$ git clone -n https://src.fedoraproject.org/rpms/f41-backgrounds.git /var/lib/mock/f45-build-8691-394/root/chroot_tmpdir/scmroot/f41-backgrounds
Cloning into '/var/lib/mock/f45-build-8691-394/root/chroot_tmpdir/scmroot/f41-backgrounds'...
$ git fetch origin 3db555709d08cb84ed98887382199b50517f87db:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/f41-backgrounds
 * [new ref]         3db555709d08cb84ed98887382199b50517f87db -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3db5557 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild