$ git clone -n https://src.fedoraproject.org/rpms/schroedinger-cat-backgrounds.git /var/lib/mock/f45-build-35663-698/root/chroot_tmpdir/scmroot/schroedinger-cat-backgrounds
Cloning into '/var/lib/mock/f45-build-35663-698/root/chroot_tmpdir/scmroot/schroedinger-cat-backgrounds'...
$ git fetch origin 2b0704231f6b25ea12e6f3aeca14e0c82b463f93:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/schroedinger-cat-backgrounds
 * [new ref]         2b0704231f6b25ea12e6f3aeca14e0c82b463f93 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2b07042 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild