$ sudo port mysql5-server-devel
$ sudo -u mysql mysql_install_db5
$ sudo launchctl load -w /Library/LaunchDaemons/org.macports.mysql5.plist
$ sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- \
    --with-mysql-include=/opt/local/include/mysql5 \
    --with-mysql-lib=/opt/local/lib/mysql5 \
    --with-mysql-config=/opt/local/lib/mysql5/bin/mysql_config