$ git clone -n https://src.fedoraproject.org/rpms/f35-backgrounds.git /var/lib/mock/f40-build-2686961-68077/root/chroot_tmpdir/scmroot/f35-backgrounds
Cloning into '/var/lib/mock/f40-build-2686961-68077/root/chroot_tmpdir/scmroot/f35-backgrounds'...
$ git fetch origin 851b231bebf999c55060707eb08a6e14175c4471:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/f35-backgrounds
 * [new ref]         851b231bebf999c55060707eb08a6e14175c4471 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 851b231 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild