Installing the MySQL Ruby Gem for Rails MySQL Support on OSX Leopard

Some special command line magic is required to install the MySQL Gem on OSX Leopard (10.5).

$ export ARCHFLAGS="-arch i386"
$ sudo gem install mysql -- --with-mysql-dir=/usr/local/mysql

I got this information from http://trac.macosforge.org/projects/ruby/wiki/Troubleshooting.