$ git clone -n https://src.fedoraproject.org/rpms/rc.git /var/lib/mock/f45-build-34363-685/root/chroot_tmpdir/scmroot/rc
Cloning into '/var/lib/mock/f45-build-34363-685/root/chroot_tmpdir/scmroot/rc'...
$ git fetch origin 8a2d52f50317e2b6bf1a0984b9c51f76426cc6c5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rc
 * [new ref]         8a2d52f50317e2b6bf1a0984b9c51f76426cc6c5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8a2d52f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild