title: Starting Rails with error
body: <p>After running Rails for a couple months without issues, I got now this ERROR when starting server (rails s) on MacBook Pro OSX 10.9.
  New projects from scratch return same ERROR.
  Any hint would be appreciated.
  Thanks in advance !!</p>
  
  <pre><code>MacBook-Pro-de-MyName:blog MyName$ rails s
      =&gt; Booting WEBrick
      =&gt; Rails 4.1.4 application starting in development on [...]
      =&gt; Run `rails server -h` for more startup options
      =&gt; Notice: server is listening on all interfaces (-.-.-.-). Consider using 127.0.0.1 (--binding option)
      =&gt; Ctrl-C to shutdown server
      [2014-08-17 21:22:30] INFO  WEBrick 1.3.1
      [2014-08-17 21:22:30] INFO  ruby 2.1.2 (2014-05-08) [x86_64-darwin13.0]
  Exiting
      /Users/MyName/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick/utils.rb:76:in
      `create_listeners': undefined method `tcp_server_sockets' for Socket:Class    
      (NoMethodError) from
      /Users/MyName/.rvm/rubies/ruby2.1.2/lib/ruby/2.1.0/webrick/server.rb:132:in `listen'
  
  [etc.]
  </code></pre>