Ruby Universal Binary Installation

To install a universal binary of Ruby, necessary to build Mac OS X packages do the following:

Install RVM

http://rvm.beginrescueend.com/

Install the Universal Binary Version of Ruby

rvm install ruby-1.9.2-head-n_ub -C --with-arch=x86_64,i386

Set Up Relative Paths

install_name_tool -id @executable_path/../lib/libruby.dylib \
    /Users/<USERNAME>/.rvm/rubies/ruby-1.9.2-head-n_ub/lib/libruby.dylib

Without this command, packages will be built with absolute path references and will not work on other computers.