$ git clone -n https://src.fedoraproject.org/rpms/f22-backgrounds.git /var/lib/mock/f39-build-1465929-33628/root/chroot_tmpdir/scmroot/f22-backgrounds
Cloning into '/var/lib/mock/f39-build-1465929-33628/root/chroot_tmpdir/scmroot/f22-backgrounds'...
$ git fetch origin e8b78e8b5fae9ac456b860e9cc581e4fe12e077d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/f22-backgrounds
 * [new ref]         e8b78e8b5fae9ac456b860e9cc581e4fe12e077d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e8b78e8 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild