title: Error installing Nokogiri 1.5.0 with rails 3.1.0 and ubuntu
body: <p>Here is the error running bundle install vendor/gems on server:</p>
  
  <pre><code>Installing nokogiri (1.5.0) with native extensions
  Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
  
          /home/dtt/.rvm/rubies/ruby-1.9.2-p290/bin/ruby extconf.rb
  checking for libxml/parser.h... no
  -----
  libxml2 is missing.  please visit http://nokogiri.org/tutorials/installing_nokogiri.html for help with installing dependencies.
  -----
  *** 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
          --without-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=/home/dtt/.rvm/rubies/ruby-1.9.2-p290/bin/ruby
          --with-zlib-dir
          --without-zlib-dir
          --with-zlib-include
          --without-zlib-include=${zlib-dir}/include
          --with-zlib-lib
          --without-zlib-lib=${zlib-dir}/lib
          --with-iconv-dir
          --without-iconv-dir
          --with-iconv-include
          --without-iconv-include=${iconv-dir}/include
          --with-iconv-lib
          --without-iconv-lib=${iconv-dir}/lib
          --with-xml2-dir
          --without-xml2-dir
          --with-xml2-include
          --without-xml2-include=${xml2-dir}/include
          --with-xml2-lib
          --without-xml2-lib=${xml2-dir}/lib
          --with-xslt-dir
          --without-xslt-dir
          --with-xslt-include
          --without-xslt-include=${xslt-dir}/include
          --with-xslt-lib
          --without-xslt-lib=${xslt-dir}/lib
  
  
  Gem files will remain installed in /vol/www/emclab/releases/20111104001151/vendor/gems/ruby/1.9.1/gems/nokogiri-1.5.0 for inspection.
  Results logged to /vol/www/emclab/releases/20111104001151/vendor/gems/ruby/1.9.1/gems/nokogiri-1.5.0/ext/nokogiri/gem_make.out
  An error occured while installing nokogiri (1.5.0), and Bundler cannot continue.
  Make sure that `gem install nokogiri -v '1.5.0'` succeeds before bundling.
  </code></pre>
  
  <p>You can skip this part. The error message is pretty much self explanatory, but the website requires a few more words explaining the code.</p>
  
  <p>Any thoughts?</p>