Tips for installing Ruby mysql module in OS X Tiger
I got my new machine and my ruby installation was pretty broken. The ruby that comes with Mac OS X is hopelessly out-of-date, and I had forgotten the things to do to get it to work.
Hand-building ruby from source to get to 1.8.4 is the first thing to do. Then I move the /usr/bin/ruby that comes with mac out of the way and create a symlink to /usr/local/bin/ruby, and ditto for /usr/lib/ruby (symlink to /usr/local/lib/ruby). That way I'm not going to get confused and launch the wrong ruby.
Then, you need to install the Ruby mysql module. I guess I'm a mysql bigot, but don't most people use mysql? I know that there are lots of choices out there, but mysql is what most people use, just for fooling around with stuff at least. Seriously.
To build ruby mysql, follow the instructions at the tmtm.org. In particular, you want to make sure that the configurator can find your mysql includes and libs, e.g.:
% ruby extconf.rb --with-mysql-dir=/usr/local/mysql