title: bundle install failed on osx 10.9
body: <p>I'm on OSX Marvericks with rvm.
  installing native extension like nokogiri from bundler failed.
  But installing from gem command works.</p>
  
  <p>I also installed latest XCode, Commandline Tool.</p>
  
  <p>I have no clue what is difference between bundle install and gem install.</p>
  
  <pre>
  $ rvm requirements
  Checking requirements for osx.
  Certificates in '/usr/local/etc/openssl/cert.pem' already are up to date.
  Requirements installation successful.
  Yusuke-no-MacBook-Air-2:doorkeeper-jp-admin yandod$ bundle install
  Fetching gem metadata from https://rubygems.org/.........
  Fetching additional metadata from https://rubygems.org/..
  Resolving dependencies...
  Using rake 10.3.1
  Using bundler 1.6.2
  Using mini_portile 0.5.3
  
  Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
  
      /Users/yandod/.rvm/rubies/ruby-2.0.0-p451-rvm/bin/ruby extconf.rb 
  /Users/yandod/.rvm/rubies/ruby-2.0.0-p451-rvm/bin/ruby: invalid option -H  (-h will show valid options) (RuntimeError)
  
  extconf failed, exit code 1
  
  Gem files will remain installed in /Volumes/Macintosh HD 2/develop/doorkeeper-jp-admin/vendor/bundle/gems/nokogiri-1.6.1 for inspection.
  Results logged to /Volumes/Macintosh HD 2/develop/doorkeeper-jp-admin/vendor/bundle/extensions/x86_64-darwin-13/2.0.0/nokogiri-1.6.1/gem_make.out
  An error occurred while installing nokogiri (1.6.1), and Bundler cannot continue.
  Make sure that `gem install nokogiri -v '1.6.1'` succeeds before bundling. 
  </pre>
  
  <p>result for gem install.</p>
  
  <pre>
  $ gem install nokogiri -v '1.6.1'
  Building native extensions.  This could take a while...
  Successfully installed nokogiri-1.6.1
  1 gem installed
  </pre>
  
  <p>versions for related software:</p>
  
  <pre>
  $ bundle --version
  Bundler version 1.6.2
  $ rvm --version
  
  rvm 1.25.25 (stable) by Wayne E. Seguin , Michal Papis  [https://rvm.io/]
  $ gem --version
  2.2.2
  </pre>
  
  <p>added:
  my bundler config</p>
  
  <pre>
  $ cat ~/.bundle/config 
  BUNDLE_PATH: ./vendor/bundle
  BUNDLE_BUILD__NOKOGIRI: --use-system-libraries --with-iconv-dir=/usr/local/opt/libiconv  --with-xml2-config=/usr/local/opt/libxml2/bin/xml2-config --with-xslt-config=/usr/local/opt/libxslt/bin/xslt-config
  </pre>