no such file to load -- mysql (MissingSourceFile)

I followed the Hivelogic tutorial to install MySQL. I was getting that error message when I do:

sudo gem install mysql

To get this to work run:

sudo env ARCHFLAGS="-arch i386" gem install mysql -- --with-mysql-dir=/usr/local/mysql --with-mysql-lib=/usr/local/mysql/lib --with-mysql-include=/usr/local/mysql/include

[All in one line]