$ git clone -n https://src.fedoraproject.org/rpms/rtrlib.git /var/lib/mock/f45-build-34736-691/root/chroot_tmpdir/scmroot/rtrlib
Cloning into '/var/lib/mock/f45-build-34736-691/root/chroot_tmpdir/scmroot/rtrlib'...
$ git fetch origin 351020fb883b05a3c276c49f04e29bbf6e883743:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rtrlib
 * [new ref]         351020fb883b05a3c276c49f04e29bbf6e883743 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 351020f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild