Notes for Mac OS X 10.6.8, Xcode 4.2.
For JRuby: Install the JDK. See http://developer.apple.com/java/download/ # Current Java version "1.6.0_26"
NOTE: Currently, Node.js is having issues building with osx-gcc-installer. The only fix is to install Xcode over osx-gcc-installer.
Required Xcode Version 3.2.1 (1613) or later, such as 3.2.6 or Xcode 4.1.
You should download the Xcode tools from developer.apple.com, since the Snow Leopard dvd install contained bugs.
# Default ruby not set. Try 'rvm alias create default <ruby>'.