Ruby-debug not working

I can't get the server to start in debugging mode: even though I have all of the correct gems installed, the server refuses to start. ``` $ gem install ruby-debug ERROR: Error installing ruby-debug: rbx-require-relative requires Ruby version ~> 1.8.7. ``` which doesn't work, other posts say to use 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 ``` Any idea what to do? Here is my 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 ```