$ git clone -n https://src.fedoraproject.org/rpms/plasma-oxygen.git /var/lib/mock/f42-bootstrap-3533872-46421/root/chroot_tmpdir/scmroot/plasma-oxygen
Cloning into '/var/lib/mock/f42-bootstrap-3533872-46421/root/chroot_tmpdir/scmroot/plasma-oxygen'...
$ git fetch origin a6add6297afde61990490f9e6ece516bad469396:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-oxygen
 * [new ref]         a6add6297afde61990490f9e6ece516bad469396 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a6add62 6.3.5