purcell/flymake-ruby — pull request #3 by aurelienbottazzini (2012-09-05 10:32:15+00:00)
Title: Added warning flag to ruby command

Allows some useful warnings. Especially if you use ruby1.9

Explained by Dave Thomas here: http://pragdave.blogs.pragprog.com/pragdave/2008/12/ruby-19-can-check-your-indentation.html