let sublime use rvm ruby; PATH: /Users/lhuang/Library/Application Support/Sublime Text 2/Packages/ruby

Ruby.sublime-build

{
  "env":{
      "PATH":"${HOME}/.rvm/bin:${PATH}"
  },
  "cmd": ["rvm-auto-ruby", "$file"],
  "file_regex": "^(...*?):([0-9]*):?([0-9]*)",
  "selector": "source.ruby"
}