$ git clone -n https://src.fedoraproject.org/rpms/jd.git /var/lib/mock/f40-build-2199508-51747/root/chroot_tmpdir/scmroot/jd
Cloning into '/var/lib/mock/f40-build-2199508-51747/root/chroot_tmpdir/scmroot/jd'...
$ git fetch origin 322aa2b44f8955deacfb4228919c53efa1423dcb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jd
 * [new ref]         322aa2b44f8955deacfb4228919c53efa1423dcb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 322aa2b update to the latest git