ruby-on-rails - 可以安装gem ruby​​-debug，但是rails server找不到

Question

我在安装 ruby​​ gems 时发现了一个非常有趣的问题

bluehat@Matapan:~/code/Amacron$ rails server --debugger
=> Booting WEBrick
=> Rails 3.0.3 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
You need to install ruby-debug to run the server in debugging mode. With gems, use 'gem install ruby-debug'
Exiting
bluehat@Matapan:~/code/Amacron$ sudo gem install ruby-debug
Successfully installed ruby-debug-0.10.4
1 gem installed
Installing ri documentation for ruby-debug-0.10.4...
Installing RDoc documentation for ruby-debug-0.10.4...
bluehat@Matapan:~/code/Amacron$ rails server --debugger
=> Booting WEBrick
=> Rails 3.0.3 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
You need to install ruby-debug to run the server in debugging mode. With gems, use 'gem install ruby-debug'
Exiting
bluehat@Matapan:~/code/Amacron$ sudo gem update ruby-debug
Updating installed gems
Nothing to update
bluehat@Matapan:~/code/Amacron$ gem --version
1.3.7
bluehat@Matapan:~/code/Amacron$ rails --version
Rails 3.0.3

系统是最新的 Ubuntu 11.04

Answer 1

您是否将此 gem 放入应用程序的 Gemfile 中？