/usr/lib/python2.7/dist-packages/root/ROOTwriter.py is in root-plugin-geom-gdml 5.34.30-0ubuntu8.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/root/../../../x86_64-linux-gnu/root5.34/ROOTwriter.py