$ git clone -n https://src.fedoraproject.org/rpms/lammps.git /var/lib/mock/f42-build-864662-172514/root/chroot_tmpdir/scmroot/lammps
Cloning into '/var/lib/mock/f42-build-864662-172514/root/chroot_tmpdir/scmroot/lammps'...
$ git fetch origin 3c30a0c65fd9a26da4cbd130a552458de3820e0c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/lammps
 * [new ref]         3c30a0c65fd9a26da4cbd130a552458de3820e0c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3c30a0c Enable heffte support