$ git clone -n https://src.fedoraproject.org/rpms/mm3d.git /var/lib/mock/f40-build-794799-139790/root/chroot_tmpdir/scmroot/mm3d
Cloning into '/var/lib/mock/f40-build-794799-139790/root/chroot_tmpdir/scmroot/mm3d'...
$ git fetch origin 70c956acaae3af18954414b4cccecc67982043eb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mm3d
 * [new ref]         70c956acaae3af18954414b4cccecc67982043eb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 70c956a upload new sources