In Lib/site.py:149 [1] _init_pathinfo call has no effect.  Looks like it's here because in the past _init_pathinfo was changing a global variable [2].  I believe that it should be changed to `known_paths = _init_pathinfo()`, in the same way as it's done in addsitedir function [3].

[1] http://hg.python.org/cpython/file/fb17969ace93/Lib/site.py#l149
[2] http://hg.python.org/cpython/annotate/ac13a6ce13e2/Lib/site.py#l102
[3] http://hg.python.org/cpython/file/fb17969ace93/Lib/site.py#l189

I suspect Kirill is right, although the function that calls addpackage() in site.py always passes in a value, so it won't change anything for Python itself, only third-party code. And addpackage() has been that way since 2004. But, in looking at the function itself, the function seems wrong without the change, so I say fix it in 3.4 but leave it out of 3.3.

And honestly that whole module needs to be cleaned up (again).

New changeset 2c0197c95ec6 by Brett Cannon in branch 'default':
Issue #16972: Have site.addpackage() consider known paths even when
http://hg.python.org/cpython/rev/2c0197c95ec6

Thanks for the bug report, Kirill!