/usr/lib/python2.7/dist-packages/schooltool.gradebook-2.1.0.egg-info/SOURCES.txt is in python-schooltool.gradebook 2.1.0-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/schooltool.gradebook-2.1.0.egg-info/../../../../share/pyshared/schooltool.gradebook-2.1.0.egg-info/SOURCES.txt