title: ERROR: Error installing cocoapods: ERROR: Failed to build gem native extension
body: <p>I am trying to install cocoapods to my MacBook Pro running with OSX 10.9.1 (new Mavericks) and after type <code>gem install cocoapods</code> I get the following error:</p>
  
  <pre><code>    Building native extensions.  This could take a while...
  ERROR:  Error installing cocoapods:
      ERROR: Failed to build gem native extension.
  
          "/usr/local/rvm/rubies/ruby-1.9.3-p194/bin/ruby" -rubygems /usr/local/rvm/gems/ruby-1.9.3-p194/gems/rake-10.1.1/bin/rake RUBYARCHDIR=/Users/rangreenberg/gems/gems/xcodeproj-0.14.1/ext RUBYLIBDIR=/Users/rangreenberg/gems/gems/xcodeproj-0.14.1/ext
  /usr/local/rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb
  checking for -std=c99 option to compiler... *** extconf.rb failed ***
  Could not create Makefile due to some reason, probably lack of
  necessary libraries and/or headers.  Check the mkmf.log file for more
  details.  You may need configuration options.
  
  Provided configuration options:
      --with-opt-dir
      --with-opt-include
      --without-opt-include=${opt-dir}/include
      --with-opt-lib
      --without-opt-lib=${opt-dir}/lib
      --with-make-prog
      --without-make-prog
      --srcdir=.
      --curdir
      --ruby=/usr/local/rvm/rubies/ruby-1.9.3-p194/bin/ruby
  /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
  You have to install development tools first.
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:491:in `block in try_compile'
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:443:in `with_werror'
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:491:in `try_compile'
      from extconf.rb:24:in `block in &lt;main&gt;'
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:790:in `block in checking_for'
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:284:in `block (2 levels) in postpone'
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:254:in `open'
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:284:in `block in postpone'
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:254:in `open'
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:280:in `postpone'
      from /usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:789:in `checking_for'
      from extconf.rb:23:in `&lt;main&gt;'
  rake aborted!
  Command failed with status (1): [/usr/local/rvm/rubies/ruby-1.9.3-p194/bin/...]
  
  Tasks: TOP =&gt; default =&gt; ext
  (See full trace by running task with --trace)
  
  
  Gem files will remain installed in /Users/rangreenberg/gems/gems/xcodeproj-0.14.1 for inspection.
  Results logged to /Users/rangreenberg/gems/gems/xcodeproj-0.14.1/ext/xcodeproj/gem_make.out
  </code></pre>