Oniguruma and Snow Leopard

If only I had better Google_fu this post by Josh Goebel would have saved me a day. The key was remembering that Oniguruma is more than than a Rails gem. So you have to (1) make sure that Oniguruma is installed (I recommend via MacPorts) and then (2) make sure that the gem can find it. Here’s what fixed it for me (thanks again to Josh):

sudo port install oniguruma5
sudo gem install oniguruma -- --with-opt-dir=/opt/local

Profit!