title: The 'json' native gem requires installed build tools
body: <p>I have <code>ruby 1.9.2p180 (2011-02-18) [i386-mingw32]</code> installed on my windows 7 machine. Now I tried to install the JSON gem using the command, "gem install json" and got the following error.</p>
  
  <pre><code>ERROR:  Error installing JSON:
      The 'json' native gem requires installed build tools.
  
  Please update your PATH to include build tools or download the DevKit
  from '[http://rubyinstaller.org/downloads][1]' and follow the instructions
  at '[http://github.com/oneclick/rubyinstaller/wiki/Development-Kit][2]'
  </code></pre>
  
  <p>Then I went and downloaded DevKit-4.5.0-20100819-1536-sfx.exe. Extracted it to C:\DevKit. And then from the command prompt, I executed the following commands.</p>
  
  <pre><code>ruby dk.rb init
  </code></pre>
  
  <p>After the above command is executed, I verified that config.yaml is generated and it has the path for my ruby folder added automatically. This is the line at the bottom of the config.yaml file          "- C:/Ruby192"</p>
  
  <pre><code>ruby dk.rb review
  </code></pre>
  
  <p>I got the message that devkit functionality will be injected into the rubies when you run "ruby dk.rb install"</p>
  
  <pre><code>ruby dk.rb install
  </code></pre>
  
  <p>I got the following message. </p>
  
  <pre><code>[INFO] RubyGems override already in place for C:/Ruby192, skipping.
  [INFO] Installing C:/Ruby192/lib/ruby/site_ruby/devkit.rb
  </code></pre>
  
  <p>Now I tried executing the JSON gem again using the command <code>gem install json</code>. Then got the same error message as before.</p>
  
  <pre><code>ERROR:  Error installing JSON:
      The 'json' native gem requires installed build tools.........
  </code></pre>
  
  <p>Am I missing something?</p>