title: Ruby gem install error
body: <p>This is an error snippet:</p>
  
  <pre><code>Using jbuilder (1.5.3) Installing jquery-rails (3.1.0) Installing json (1.8.1) Gem::Installer::ExtensionBuildError: ERROR:
  Failed to build gem native extension .
  
      c:/RailsInstaller/Ruby1.9.3/bin/ruby.exe extconf.rb c:/RailsInstaller/Ruby1.9.3/bin/ruby.exe: No such file or directory
  -- extconf.r b (LoadError)
  
  Gem files will remain installed in
  c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9 .1/gems/json-1.8.1 for
  inspection. Results logged to
  c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/json-1.8.
  1/ext/json/ext/generator/gem_make.out An error occurred while
  installing json (1.8.1), and Bundler cannot continue. Make sure that
  `gem install json -v '1.8.1'` succeeds before bundling.
  </code></pre>
  
  <p>Entering <code>gem install json -v</code> returns:</p>
  
  <pre><code>'1.8.1' Temporarily enhancing PATH to include DevKit... Building
  native extensions.  This could take a while... ERROR:  Error
  installing json:
          ERROR: Failed to build gem native extension.
  
          c:/RailsInstaller/Ruby1.9.3/bin/ruby.exe extconf.rb c:/RailsInstaller/Ruby1.9.3/bin/ruby.exe: No such file or directory
  -- extconf.r b (LoadError)
  
  
  Gem files will remain installed in
  c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9 .1/gems/json-1.8.1 for
  inspection. Results logged to
  c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/json-1.8.
  1/ext/json/ext/generator/gem_make.out
  </code></pre>
  
  <p>Entering <code>bundle install</code> returns:</p>
  
  <pre><code>Bundler::GemfileNotFound
  </code></pre>
  
  <p>Entering <code>cd qwerty</code> returns:</p>
  
  <pre><code>pmakamgovind@CSCINDAE751352 ~/Desktop/ruby/qwerty $ rails s
  ←[31mCould not find gem 'rails (= 4.0.2) x86-mingw32' in the gems
  available on t his machine.←[0m ←[33mRun `bundle install` to install
  missing gems.←[0m
  </code></pre>