Ruby升级后no such file to load — readline解决办法

升级ruby和rails后进入script/consle出现: 代码如下: /usr/local/lib/ruby/1.8/irb/completion.rb:10:in `require’: no such file to load — readline (LoadError) from /usr/local/lib/ruby/1.8/irb/completion.rb:10 from /usr/local/lib/ruby/1.8/irb/init.rb:252:in `require’ from /usr/local/lib