I just went through the same pain… here’s what worked for me:
- Download / install the 64-bit MySQL 5.1.37 from mysql.com
- run the following commands:
sudo gem update --system sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config
I also uninstalled all mysql gems that were floating around from my 10.5 days, that may do it if the above doesn’t work for you 🙂