Does Ruby have any tools along the lines of pylint for analyzing source code for errors and simple coding standards?
It would be nice if it could be integrated with cruisecontrolrb for continuous integration.
Or does everyone write such good tests that they don't need source code checkers!
I reviewed a bunch of Ruby tools that are available here
http://devver.wordpress.com/2008/10/03/ruby-tools-roundup/
most of the tools were mentioned by webmat, but if you want more information I go pretty in depth with examples.
I also highly recommend using Metric-Fu it gives you a on gem/plugin install of 3 of the more popular tools and is built with cruisecontrolrb integration in mind.
The creator has a great post that should help get you up and running in no time.
http://jakescruggs.blogspot.com/2008/04/dead-simple-rails-metrics-with-metricfu.html
There has been a lot of activity in Ruby tools lately which I think is a good sign of a growing and maturing language.