title: Check gem version number
body: <p>My setup: Rails 3.0.9, Ruby 1.9.2</p>
  
  <p>I want to check the gem version for my app through the Rails console. In my gemfile, I have </p>
  
  <pre><code>gem 'rack', '1.2.3'
  </code></pre>
  
  <p>Ran bundle install after. In the Rails console, </p>
  
  <pre><code>&gt;&gt; Rack.version
  =&gt; "1.1"
  </code></pre>
  
  <p>Any idea why?</p>
  
  <p><strong>UPDATE</strong></p>
  
  <pre><code>Gemfile.lock
  
  GEM
    remote: http://rubygems.org/
    specs:
      actionpack (3.0.9)
        ...
        rack (~&gt; 1.2.1)
        ...
  
      rack (1.2.3)
  
      rack-mount (0.6.14)
        rack (&gt;= 1.0.0)
  
      warden (1.0.4)
        rack (&gt;= 1.0)
  
  DEPENDENCIES
  ...  
  rack (= 1.2.3)
  ...
  </code></pre>
  
  <p>There are several rack versions listed in <code>gemfile.lock</code>.</p>