rails服务器处于调试模式

当我尝试使用“rails server --debugger”在调试器模式下运行rails服务器时 . 我在我的控制台上收到以下错误 .

/home/navyug/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/ext/module.rb:36:in `const_missing': uninitialized constant Debugger::LocalInterface::Readline (NameError)
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/ruby-debug19-0.11.6/cli/ruby-debug/interface.rb:55:in `block (2 levels) in initialize'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/ruby-debug19-0.11.6/cli/ruby-debug/interface.rb:53:in `each'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/ruby-debug19-0.11.6/cli/ruby-debug/interface.rb:53:in `block in initialize'
    from /home/navyug/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/open-uri.rb:35:in `open'
    from /home/navyug/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/open-uri.rb:35:in `open'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/ruby-debug19-0.11.6/cli/ruby-debug/interface.rb:52:in `initialize'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/ruby-debug19-0.11.6/cli/ruby-debug/processor.rb:61:in `new'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/ruby-debug19-0.11.6/cli/ruby-debug/processor.rb:61:in `initialize'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/ruby-debug19-0.11.6/cli/ruby-debug.rb:9:in `new'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/ruby-debug19-0.11.6/cli/ruby-debug.rb:9:in `<module:Debugger>'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/ruby-debug19-0.11.6/cli/ruby-debug.rb:8:in `<top (required)>'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.7/lib/rails/rack/debugger.rb:9:in `initialize'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/server.rb:295:in `new'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/server.rb:295:in `block in build_app'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/server.rb:291:in `reverse_each'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/server.rb:291:in `build_app'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/server.rb:252:in `start'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.7/lib/rails/commands/server.rb:70:in `start'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.7/lib/rails/commands.rb:55:in `block in <top (required)>'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.7/lib/rails/commands.rb:50:in `tap'
    from /home/navyug/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.7/lib/rails/commands.rb:50:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

RubyGems环境

• RUBYGEMS版本：1.8.24

• RUBY VERSION：1.9.3（2012-04-20 patchlevel 194）[i686-linux]

• 安装目录：/home/navyug/.rvm/gems/ruby-1.9.3-p194

• RUBY EXECUTABLE：/home/navyug/.rvm/rubies/ruby-1.9.3-p194/bin/ruby

• 可执行目录：/home/navyug/.rvm/gems/ruby-1.9.3-p194/bin

• RUBYGEMS PLATFORMS：

• 红宝石

• x86-linux

• GEM路径：

• /home/navyug/.rvm/gems/ruby-1.9.3-p194

• /home/navyug/.rvm/gems/ruby-1.9.3-p194@global

• GEM配置：

• ：update_sources => true

• ：verbose => true

• ：benchmark => false

• ：backtrace => false

• ：bulk_threshold => 1000

• 远程来源：

• http://rubygems.org/