Solution to error from “gem install mysql”

On Mac/CentOS, sometimes you get errors when trying to “gem install mysql”.
To fix this, if your Mac is intel based, do:

$ sudo -s
$ ARCHFLAGS=”-arch i386″ gem install mysql — –with-mysql-dir=/usr/local/mysql

you might want to change “/usr/local/mysql” part to whatever is correct on your system.