$ git clone -n https://src.fedoraproject.org/rpms/leonidas-backgrounds.git /var/lib/mock/f45-build-15672-478/root/chroot_tmpdir/scmroot/leonidas-backgrounds
Cloning into '/var/lib/mock/f45-build-15672-478/root/chroot_tmpdir/scmroot/leonidas-backgrounds'...
$ git fetch origin 4ecb91a38ff39bd3773c212977d922b4027669ad:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/leonidas-backgrounds
 * [new ref]         4ecb91a38ff39bd3773c212977d922b4027669ad -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4ecb91a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild