Tox 1.4.2 does not parse comments in the environment list
Using tox 1.4.2 and python 2.7 on OSX I get
ERROR: unknown environment 'py32 # Python 3.1 and 3.0 might work as well.'
when running tox with the toxfile here: https://github.com/erikrose/more-itertools/blob/c0339068f094933504d095bb0d2c40577acf7c56/tox.ini
Moving the comment to a different line fixes the issue.