title: gem install rails build error failed to build gem native extension
body: <p>My main goal is to make Redmine work along with WAMPServer. I followed these steps : <a href="https://stackoverflow.com/questions/2025449/how-to-install-ruby-on-rails-alongside-wampserver?lq=1">How to install Ruby on Rails alongside WampServer?</a></p>
  
  <p>When i have to install rails, a build error seems to happen in my command line</p>
  
  <p>Here's my error : </p>
  
  <blockquote>
    <p>c:\wamp\ruby\gem install rails</p>
    
    <p>Temporarily enhancing PATH to include DevKit...</p>
    
    <p>Building native extensions. This could take a while...</p>
    
    <p>ERROR: Error installing tzinfo:</p>
    
    <p>ERROR: Failed to build gem native extension.</p>
    
    <p>C:/wamp/ruby/bin/ruby.exe extconf.rb
    creating Makefile</p>
    
    <p>make
    gcc -I. -I. -IC:/wamp/ruby/lib/ruby/1.8/i386-mingw32 -I.  -g -O2 -DFD_SETSIZE=256    -c atomic_reference.c
    atomic_reference.c: In function 'ir_compare_and_set':
    atomic_reference.c:75:2: error: #error No CAS operation available for this platform
    make: *** [atomic_reference.o] Error 1</p>
  </blockquote>
  
  <p>I use Windows 7 64 bits and my versions are ruby 1.8.7, gem 1.3.7 </p>