title: Why won't bundler install JSON gem?
body: <p>I get the following error when attempting to run <code>cap production deploy</code>. </p>
  
  <pre><code>DEBUG [dc362284]    Bundler::GemNotFound: Could not find json-1.8.1.gem for installation
  DEBUG [dc362284]    An error occurred while installing json (1.8.1), and Bundler cannot continue.
  DEBUG [dc362284]    Make sure that `gem install json -v '1.8.1'` succeeds before bundling.
  </code></pre>
  
  <p>It may be important to note that this deployment was working, than I upgraded to Ruby 2.1.0 to remove an encoding error.  I upgraded locally which worked fine. I ran <code>rvm install 2.1.0</code> and <code>rvm use 2.1.0</code> then changed my <code>.ruby-version</code> file to reflect this Ruby upgrade.</p>
  
  <p>The <code>bundle install</code> command works locally, but produces the same above error when I ssh onto the destination server and run this command.    </p>
  
  <p>If I run <code>gem list</code> I can see this in the list of gems.</p>
  
  <pre><code>...
  jquery-rails (3.0.4)
  json (1.8.1)
  less (2.3.2)
  ...
  </code></pre>
  
  <p>If I try the recommended solution <code>gem install json -v '1.8.1'</code> Locally and on the destination server I get the following output:</p>
  
  <pre><code>Building native extensions.  This could take a while...
  Successfully installed json-1.8.1
  Parsing documentation for json-1.8.1
  Done installing documentation for json after 0 seconds
  1 gem installed
  </code></pre>
  
  <p>So it appears the gem is installed, right?  Why is this happening? How can I solve this?  Any help would be greatly appreciated.  </p>