In my previous article I talked about using environment.plist to set environment variables in RubyMine. Well, it turns out that environment.plist doesn’t always work. Specifically, if you start RubyMine from Spotlight RubyMine has a different parent process that DOESN’T take into account the environment.plist file. It DOES work if you open RubyMine using the Dock or Quicksilver, though. Who would have guessed? This easily killed a day or so of troubleshooting on my current project.
So, to really solve this problem, it turns out you have to put your environment variables in /etc/launchd.conf like this:

setenv M2_HOME /opt/maven/2.0.9

For more details, check out this blog post and this blog post.