rails c 的时候出错- - cannot load such file -- readline

cnlirxio — Sat, 17 Aug 2013 17:47:01 +0800

root@localhost:~/sample_app# rails c
/usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/completion.rb:9:in `require': cannot load such file -- readline (LoadError)
        from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/irb/completion.rb:9:in `<top (required)>'
        from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands/console.rb:3:in `require'
        from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands/console.rb:3:in `<top (required)>'
        from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:53:in `require'
        from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:53:in `<top (required)>'
        from bin/rails:4:in `require'
        from bin/rails:4:in `<main>'

怎么能解决呢？

[求助] RuntimeError

cnlirxio — Fri, 05 Jul 2013 16:04:50 +0800

RuntimeError: attr_accessible is extracted out of Rails into a gem. Please use new recommended protection model for params(strong_parameters) or add protected_attributes to your Gemfile to use old one.

在看http://guides.ruby-china.org/getting_started.html
在 9.6 节的时候出现了这样的错误。看不懂求解答。

cnlirxio (意品悠游)

rails c 的时候出错- - cannot load such file -- readline

[求助] RuntimeError