ruby-on-rails – Ruby-debug无法正常工作

即使我安装了所有正确的gem,服务器也拒绝启动.

$gem install ruby-debug
ERROR:  Error installing ruby-debug:
       rbx-require-relative requires Ruby version ~> 1.8.7.

哪个不起作用,其他帖子说使用ruby-debug19：

David@DAVID-PC /c/triton6 
$gem install ruby-debug19
Successfully installed ruby-debug19-0.11.6
1 gem installed
Installing ri documentation for ruby-debug19-0.11.6...
Installing RDoc documentation for ruby-debug19-0.11.6...

David@DAVID-PC /c/triton6 
$rails server --debug
=> Booting WEBrick
=> Rails 3.1.3 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

知道该怎么办？

这是我的Gemfile：

source 'http://rubygems.org'

gem 'rails','3.1.3'

# Bundle edge Rails instead:
# gem 'rails',:git => 'git://github.com/rails/rails.git'

gem 'sqlite3'
gem 'ruby-debug19'
gem 'execjs'
gem 'ruby-debug-ide'

# Gems used only for assets and not required
# in production environments by default.
group :assets do
gem 'sass-rails','~> 3.1.5'
gem 'coffee-rails','~> 3.1.1'
gem 'uglifier','>= 1.0.3'
end

gem 'jquery-rails'

# To use ActiveModel has_secure_password
# gem 'bcrypt-ruby','~> 3.0.0'

# Use unicorn as the web server
# gem 'unicorn'

# Deploy with Capistrano
# gem 'capistrano'

# To use debugger
# gem 'ruby-debug19',:require => 'ruby-debug'

group :test do
# Pretty printed test output
gem 'turn','0.8.2',:require => false
end