$ git clone -n https://src.fedoraproject.org/rpms/furnace.git /var/lib/mock/f45-build-9337-401/root/chroot_tmpdir/scmroot/furnace
Cloning into '/var/lib/mock/f45-build-9337-401/root/chroot_tmpdir/scmroot/furnace'...
$ git fetch origin 312258f012c46bd79d052120729cfa9f7018d088:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/furnace
 * [new ref]         312258f012c46bd79d052120729cfa9f7018d088 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 312258f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild