title: Bundle install fails to install libxml-ruby
body: <p>I'm a new to Ruby world and I need to clone an existing project.</p>
  
  <p>The instructions are:</p>
  
  <pre><code>source .env.development
  bundle install
  </code></pre>
  
  <p>But it fails with:</p>
  
  <pre><code>Using libv8 3.16.14.15
  Fetching libxml-ruby 2.9.0
  Installing libxml-ruby 2.9.0 with native extensions
  Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
  
  current directory: /Users/vlad/.rvm/gems/ruby-2.3.1/gems/libxml-ruby-2.9.0/ext/libxml
  /Users/vlad/.rvm/rubies/ruby-2.3.1/bin/ruby -r ./siteconf20181109-46682-fvgifh.rb extconf.rb --use-system-libraries
  checking for libxml/xmlversion.h in /opt/include/libxml2,/opt/local/include/libxml2,/usr/local/include/libxml2,/usr/include/libxml2... no
  *** 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/vlad/.rvm/rubies/ruby-2.3.1/bin/$(RUBY_BASE_NAME)
  --with-xml2-config
  --without-xml2-config
  --with-xml2-dir
  --without-xml2-dir
  --with-xml2-include
  --without-xml2-include=${xml2-dir}/include
  --with-xml2-lib
  --without-xml2-lib=${xml2-dir}/lib
   extconf failure: need libxml2.
  
      Install the library or try one of the following options to extconf.rb:
  
        --with-xml2-config=/path/to/xml2-config
        --with-xml2-dir=/path/to/libxml2
        --with-xml2-lib=/path/to/libxml2/lib
        --with-xml2-include=/path/to/libxml2/include
  
  
  To see why this extension failed to compile, please check the mkmf.log which can be found here:
  
    /Users/vlad/.rvm/gems/ruby-2.3.1/extensions/x86_64-darwin-18/2.3.0/libxml-ruby-2.9.0/mkmf.log
  
  extconf failed, exit code 1
  
  Gem files will remain installed in /Users/vlad/.rvm/gems/ruby-2.3.1/gems/libxml-ruby-2.9.0 for inspection.
  Results logged to /Users/vlad/.rvm/gems/ruby-2.3.1/extensions/x86_64-darwin-18/2.3.0/libxml-ruby-2.9.0/gem_make.out
  
  An error occurred while installing libxml-ruby (2.9.0), and Bundler cannot continue.
  Make sure that `gem install libxml-ruby -v '2.9.0'` succeeds before bundling.
  
  In Gemfile:
    upnxt_community_lib_common was resolved to 1.7.49, which depends on
      upnxt_processing_lib_document was resolved to 2.0.0, which depends on
        libxml-
  </code></pre>
  
  <p>If I want to execute the command that is suggested "gem install libxml-ruby -v '2.9.0'" I get the same error. </p>
  
  <p>Operating System: MacOS Mojave, version 10.14.
  Ruby version needed for the project: ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-darwin18]</p>
  
  <p>I also tried <a href="https://stackoverflow.com/a/23550421/3018671">this</a> but it didn't helped.</p>
  
  <p>Thanks in advance for any help!</p>