vajrasky, one more errno to consider:

[Errno 39] Directory not empty: '/tmp/bar'

This is when renaming a directory: src directory exists; dst directory exists and is non-empty.

In 3.4 Beta1, this error message now includes the src instead of the dst (flipped behaviour from Python 3.3). I'm not sure whether this changed because of changes being tracked in this bug on not, so I filed a separate issue: http://bugs.python.org/issue20093