$ git clone -n https://src.fedoraproject.org/rpms/slrn.git /var/lib/mock/f45-build-36047-701/root/chroot_tmpdir/scmroot/slrn
Cloning into '/var/lib/mock/f45-build-36047-701/root/chroot_tmpdir/scmroot/slrn'...
$ git fetch origin 61d022f86ea987f95474f778d4015196b63d4c49:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/slrn
 * [new ref]         61d022f86ea987f95474f778d4015196b63d4c49 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 61d022f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild