mysql2 和 ruby 1.9.2 的错误处理
sudo install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql/lib/libmysqlclient.18.dylib /Users/keo/.rvm/gems/ruby-1.9.2-p290/gems/mysql2-0.3.7/lib/mysql2/mysql2.bundle

还有一个装mongrel的出错

出错提示如下：
$ sudo gem1.9 install mongrel --pre> Building native extensions. This could take a while...> Successfully installed mongrel-1.2.0.pre2> 1 gem installed

最好是改gemfile如下：

gem 'mongrel','~> 1.2.0.pre2'