matplotlib/matplotlib — pull request #2703 by androomerrill (2014-01-04 21:11:24+00:00)
Title: Updating regex used to split sphinx version string.

The latest stable sphinx version string is '1.2+'.
The regex pattern '[a-z]' fails to match the '+' character
leading to a `ValueError` being raised when it attempts to
cast '2+' to an int. Replacing '[a-z]' with '[^0-9]' resolves this.