title: Error in installing json gem for ruby in windows
body: <p>While I am trying to create the new rails project, I face to error that is related to the lack of json gem.</p>
  
  <p>When I try to install json gem, this error happens:</p>
  
  <pre><code>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:/Ruby22-x64/bin/ruby.exe extconf.rb
  creating Makefile
  
  make "DESTDIR=" clean
  
  make "DESTDIR="
  generating generator-x64-mingw32.def
  compiling generator.c
  In file included from c:/Ruby22-x64/include/ruby-2.2.0/ruby/ruby.h:29:0,
                   from c:/Ruby22-x64/include/ruby-2.2.0/ruby.h:33,
                   from ../fbuffer/fbuffer.h:5,
                   from generator.c:1:
  c:/Ruby22-x64/include/ruby-2.2.0/ruby/defines.h:26:19: fatal error: stdio.h: No such file or directory
  compilation terminated.
  make: *** [generator.o] Error 1
  
  make failed, exit code 2
  
  Gem files will remain installed in C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/json-1.8.3 for inspection.
  Results logged to C:/Ruby22-x64/lib/ruby/gems/2.2.0/extensions/x64-mingw32/2.2.0/json-1.8.3/gem_make.out
  </code></pre>