title: In production mode I am getting - No such file to load -- ruby-debug (LoadError)
body: <p>I am using Rails 3.2.1 and the 'ruby-debug19' line has been commented out in the Gemfile.
  When I start the server in development mode, the server starts up without any problem. However, when I start my server in production mode (rails server -e production, I endup getting the following error (see stack trace below):</p>
  
  <pre><code>... `rescue in depend_on': No such file to load -- ruby-debug (LoadError)
  </code></pre>
  
  <p>I have spent quite bit of time trying to figure out who is requiring reby-debug without any luck. Not sure what to include except my Gemfile and the stack. I would really appreciate any help. </p>
  
  <p>One more piece of info: line 5 in my environment.rb file is just calling "Application.initialize!"</p>
  
  <p>Gemfile:</p>
  
  <pre><code>gem 'rails', '3.2.1'
  gem 'mysql'
  gem 'gravatar_image_tag', '0.1.0'
  gem "devise", "&gt;= 1.4.9"
  gem "paperclip", "~&gt; 2.0"
  gem 'jquery-rails'
  gem 'aws-sdk'
  gem 'aws-s3', :require =&gt; 'aws/s3'
  gem 'formtastic'
  gem 'cancan'    
  gem 'kaminari'
  gem 'date_validator'
  gem 'simple_form'
  gem 'heroku'
  
  gem 'pg', :group =&gt; :production
  
  # Gems used only for assets and not required
  # in production environments by default.
  group :assets do
    gem 'sass-rails', "  ~&gt; 3.2.3"
    gem 'coffee-rails', "~&gt; 3.2.1"
    gem 'uglifier', '&gt;= 1.0.3'
  end
  
  gem 'annotate','2.4.1.beta1', :group =&gt; :development
  gem 'nifty-generators',       :group =&gt; :development
  
  gem 'rspec-rails', '2.6.1.beta1', :group =&gt; [:development, :test]
  gem 'faker', '0.3.1',             :group =&gt; [:development, :test]
  gem 'rspec', '2.6',               :group =&gt; [:test, :development]
  gem 'populator',                  :group =&gt; [:development, :test]
  
  #gem 'ruby-debug19', :require =&gt; 'ruby-debug', :group =&gt; [:development, :test]
  
  gem "factory_girl_rails", "&gt;= 1.1.0", :group =&gt; :test
  gem "cucumber-rails", "&gt;= 1.0.2",     :group =&gt; :test
  gem "pickle", "&gt;=0.4.10",             :group =&gt; :test
  gem "capybara", "&gt;= 1.0.1",           :group =&gt; :test
  gem "database_cleaner", "&gt;= 0.6.7",   :group =&gt; :test
  gem "launchy", "&gt;= 2.0.5",            :group =&gt; :test
  gem "email_spec",                     :group =&gt; :test
  gem 'guard-rspec',                    :group =&gt; :test
  gem "mocha",                          :group =&gt; :test
  </code></pre>
  
  <p>And here is the stack trace:</p>
  
  <pre><code>➜  taskfree git:(master) ✗ bundle exec rails server -e production
  =&gt; Booting WEBrick
  =&gt; Rails 3.2.1 application starting in production on http://0.0.0.0:3000
  =&gt; Call with -d to detach
  =&gt; Ctrl-C to shutdown server
  Exiting
  /usr/local/rvm/gems/ruby-1.9.2-p290/gems/activesupport- 3.2.1/lib/active_support/dependencies.rb:317:in `rescue in depend_on': No such file to load -- ruby-debug (LoadError)
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/activesupport3.2.1/lib/active_support/dependencies.rb:312:in `depend_on'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:225:in `require_dependency'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/engine.rb:439:in `block (2 levels) in eager_load!'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/engine.rb:438:in `each'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/engine.rb:438:in `block in eager_load!'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/engine.rb:436:in `each'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/engine.rb:436:in `eager_load!'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/application/finisher.rb:53:in `block in &lt;module:Finisher&gt;'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/initializable.rb:30:in `instance_exec'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/initializable.rb:30:in `run'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/initializable.rb:55:in `block in run_initializers'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/initializable.rb:54:in `each'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/initializable.rb:54:in `run_initializers'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/application.rb:136:in `initialize!'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/railtie/configurable.rb:30:in `method_missing'
  from /Users/bidhan/code/taskfree/config/environment.rb:5:in `&lt;top (required)&gt;'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `require'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `block in require'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:236:in `load_dependency'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `require'
  from /Users/bidhan/code/taskfree/config.ru:4:in `block in &lt;main&gt;'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
  from /Users/bidhan/code/taskfree/config.ru:1:in `new'
  from /Users/bidhan/code/taskfree/config.ru:1:in `&lt;main&gt;'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/rack-1.4.1/lib/rack/server.rb:200:in `app'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/commands/server.rb:46:in `app'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/rack-1.4.1/lib/rack/server.rb:252:in `start'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/commands/server.rb:70:in `start'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/commands.rb:55:in `block in &lt;top (required)&gt;'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/commands.rb:50:in `tap'
  from /usr/local/rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/commands.rb:50:in `&lt;top (required)&gt;'
  from script/rails:6:in `require'
  from script/rails:6:in `&lt;main&gt;'
  </code></pre>
  
  <p>And here is the output when I just start my server in development mode:</p>
  
  <pre><code>➜  taskfree git:(master) ✗ bundle exec rails server              
  =&gt; Booting WEBrick
  =&gt; Rails 3.2.1 application starting in development on http://0.0.0.0:3000
  =&gt; Call with -d to detach
  =&gt; Ctrl-C to shutdown server
  [2012-02-17 15:09:24] INFO  WEBrick 1.3.1
  [2012-02-17 15:09:24] INFO  ruby 1.9.2 (2011-07-09) [x86_64-darwin10.5.0]
  [2012-02-17 15:09:24] INFO  WEBrick::HTTPServer#start: pid=33798 port=3000
  </code></pre>