/usr/lib/pyshared/python2.7/persistent/cPickleCache.so is in python-zodb 1:3.10.5-0ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/pyshared/python2.7/persistent/../../../python2.7/dist-packages/persistent/cPickleCache.so