$ git clone -n https://src.fedoraproject.org/rpms/plasma-pa.git /var/lib/mock/f42-build-side-1-3510443-46033/root/chroot_tmpdir/scmroot/plasma-pa
Cloning into '/var/lib/mock/f42-build-side-1-3510443-46033/root/chroot_tmpdir/scmroot/plasma-pa'...
$ git fetch origin 1584f670759e0166d21ccd3e34090434783d1a34:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-pa
 * [new ref]         1584f670759e0166d21ccd3e34090434783d1a34 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1584f67 6.3.4