$ git clone -n https://src.fedoraproject.org/rpms/plexus-xml.git /var/lib/mock/f42-build-3354256-45019/root/chroot_tmpdir/scmroot/plexus-xml
Cloning into '/var/lib/mock/f42-build-3354256-45019/root/chroot_tmpdir/scmroot/plexus-xml'...
$ git fetch origin 338e8e2cd260abea5330ed44b27d466ad50d26a9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plexus-xml
 * [new ref]         338e8e2cd260abea5330ed44b27d466ad50d26a9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 338e8e2 Remove javadoc subpackage