title: bundle install json installation fails
body: <p>I'm using the ruby on rails tutorial here:</p>
  
  <blockquote>
    <p><a href="http://ruby.railstutorial.org/chapters/modeling-and-viewing-users-one#top" rel="nofollow">http://ruby.railstutorial.org/chapters/modeling-and-viewing-users-one#top</a></p>
  </blockquote>
  
  <p>and I ran into problems when using the bundle exec rake db:migrate command. It said</p>
  
  <blockquote>
    <p>Could not find json-1.6.3 in any of the sources.</p>
  </blockquote>
  
  <p>So I used the command <code>gem install json -v '1.6.3'</code>, and everything seemed to work fine. Then I tried running <code>bundle exec rake db:migrate</code> again, and it failed with the same message, could not find json.</p>
  
  <p>I believe a clue to the problem is that when I use the command <code>bundle install</code>, this message pops up when trying to install json 1.6.3:</p>
  
  <pre><code>Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
  /Users/chuckyuan/.rvm/rubies/ruby-1.9.2-p290/bin/ruby extconf.rb 
  creating Makefile
  
  make
  Makefile:148: *** target pattern contains no `%'.  Stop.
  
  
  Gem files will remain installed in /Users/chuckyuan/Documents/rails_projects/sample_app/db:migrate/ruby/1.9.1/gems/json-1.6.3 for inspection.
  Results logged to /Users/chuckyuan/Documents/rails_projects/sample_app/db:migrate/ruby/1.9.1/gems/json-1.6.3/ext/json/ext/parser/gem_make.out
  An error occured while installing json (1.6.3), and Bundler cannot continue.
  Make sure that `gem install json -v '1.6.3'` succeeds before bundling.
  </code></pre>
  
  <p>When I create a new rails project and run the same commands, everything works. Thanks in advance for your help.</p>