/usr/lib/python2.6/dist-packages/mocker-1.0.egg-info/SOURCES.txt is in python-mocker 1.0-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.6/dist-packages/mocker-1.0.egg-info/../../../../share/pyshared/mocker-1.0.egg-info/SOURCES.txt