title: Install Nokogiri 1.6.1 under Ruby 2.0.0p353 (rvm based installation) fails (OSX Mavericks)?
body: <p>I've tried to install Nokogiri 1.6.1 under Ruby and RVM but is failing with the following error:</p>
  
  <pre><code>Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
  
  /Users/lmo0/.rvm/rubies/ruby-2.0.0-p353/bin/ruby extconf.rb 
  Extracting libxml2-2.8.0.tar.gz into tmp/x86_64-apple-darwin13.0.0/ports/libxml2/2.8.0... OK
  Running 'configure' for libxml2 2.8.0... OK
  Running 'compile' for libxml2 2.8.0... OK
  Running 'install' for libxml2 2.8.0... OK
  Activating libxml2 2.8.0 (from /Users/lmo0/.rvm/gems/ruby-2.0.0-p353/gems/nokogiri-1.6.1/ports/x86_64-apple-darwin13.0.0/libxml2/2.8.0)...
  Extracting libxslt-1.1.26.tar.gz into tmp/x86_64-apple-darwin13.0.0/ports/libxslt/1.1.26... OK
  Running 'configure' for libxslt 1.1.26... ERROR, review 'tmp/x86_64-apple-darwin13.0.0/ports/libxslt/1.1.26/configure.log' to see what happened.
  *** 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=/Users/lmo0/.rvm/rubies/ruby-2.0.0-p353/bin/ruby
  /Users/lmo0/.rvm/gems/ruby-2.0.0-p353/gems/mini_portile-0.5.2/lib/mini_portile.rb:265:in `block in execute': Failed to complete configure task (RuntimeError)
      from /Users/lmo0/.rvm/gems/ruby-2.0.0-p353/gems/mini_portile-0.5.2/lib/mini_portile.rb:257:in `chdir'
      from /Users/lmo0/.rvm/gems/ruby-2.0.0-p353/gems/mini_portile-0.5.2/lib/mini_portile.rb:257:in `execute'
      from /Users/lmo0/.rvm/gems/ruby-2.0.0-p353/gems/mini_portile-0.5.2/lib/mini_portile.rb:65:in `configure'
      from /Users/lmo0/.rvm/gems/ruby-2.0.0-p353/gems/mini_portile-0.5.2/lib/mini_portile.rb:108:in `cook'
      from extconf.rb:101:in `block in &lt;main&gt;'
      from extconf.rb:131:in `call'
      from extconf.rb:131:in `block in &lt;main&gt;'
      from extconf.rb:122:in `tap'
      from extconf.rb:122:in `&lt;main&gt;'
  
  
  Gem files will remain installed in /Users/lmo0/.rvm/gems/ruby-2.0.0-p353/gems/nokogiri-1.6.1 for inspection.
  Results logged to /Users/lmo0/.rvm/gems/ruby-2.0.0-p353/gems/nokogiri-1.6.1/ext/nokogiri/gem_make.out
  </code></pre>