$ git clone -n https://src.fedoraproject.org/rpms/openmpi.git /var/lib/mock/f40-build-2617760-64455/root/chroot_tmpdir/scmroot/openmpi
Cloning into '/var/lib/mock/f40-build-2617760-64455/root/chroot_tmpdir/scmroot/openmpi'...
$ git fetch origin 7c043588b79f53af04a4d0fc72de1044dc194126:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/openmpi
 * [new ref]         7c043588b79f53af04a4d0fc72de1044dc194126 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7c04358 Properly check valgrind arches