$ git clone -n https://src.fedoraproject.org/rpms/laughlin-backgrounds.git /var/lib/mock/f45-build-15623-477/root/chroot_tmpdir/scmroot/laughlin-backgrounds
Cloning into '/var/lib/mock/f45-build-15623-477/root/chroot_tmpdir/scmroot/laughlin-backgrounds'...
$ git fetch origin e5244ddf715f84c9da947b6e2ab2af20ae8fa1ca:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/laughlin-backgrounds
 * [new ref]         e5244ddf715f84c9da947b6e2ab2af20ae8fa1ca -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e5244dd Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild