$ git clone -n https://src.fedoraproject.org/rpms/openmpi.git /var/lib/mock/f40-build-2173416-51063/root/chroot_tmpdir/scmroot/openmpi
Cloning into '/var/lib/mock/f40-build-2173416-51063/root/chroot_tmpdir/scmroot/openmpi'...
$ git fetch origin c510a02ce6bba0f0ce3493638113004b38ac3993:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/openmpi
 * [new ref]         c510a02ce6bba0f0ce3493638113004b38ac3993 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c510a02 Update to 5.0.1