enthought/traits — pull request #176 by pradyun (2014-05-05 07:17:11+00:00)
Title: Fix TraitListObject.sort for Python 3, along with tests.

In Python 3, list.sort no longer takes a cmp keyword argument.
But TraitListObject.sort called list.sort with the cmp argument. This caused a TypeError to be raised by list.sort.

It is now appropriately handled and a TypeError is raised if the cmp keyword is passed.