fastlane: Unable to install "Failed to build gem native extension."

Hopefully someone can help me with fixing this install issue. I run

sudo gem install fastlane --verbose

I get

Extracting libxml2-2.9.2.tar.gz into tmp/x86_64-apple-darwin14/ports/libxml2/2.9.2... OK
Running patch with /Library/Ruby/Gems/2.0.0/gems/nokogiri-1.6.6.2/ports/patches/libxml2/0001-Revert-Missing-initialization-for-the-catalog-module.patch...
Running 'patch' for libxml2 2.9.2... OK
Running patch with /Library/Ruby/Gems/2.0.0/gems/nokogiri-1.6.6.2/ports/patches/libxml2/0002-Fix-missing-entities-after-CVE-2014-3660-fix.patch...
Running 'patch' for libxml2 2.9.2... OK
Running 'configure' for libxml2 2.9.2... OK
Running 'compile' for libxml2 2.9.2... ERROR, review '/Library/Ruby/Gems/2.0.0/gems/nokogiri-1.6.6.2/ext/nokogiri/tmp/x86_64-apple-darwin14/ports/libxml2/2.9.2/compile.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
    --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=/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby
    --help
    --clean
    --use-system-libraries
    --enable-static
    --disable-static
    --with-zlib-dir
    --without-zlib-dir
    --with-zlib-include
    --without-zlib-include=${zlib-dir}/include
    --with-zlib-lib
    --without-zlib-lib=${zlib-dir}/lib
    --enable-cross-build
    --disable-cross-build
/Library/Ruby/Gems/2.0.0/gems/mini_portile-0.6.2/lib/mini_portile.rb:279:in `block in execute': Failed to complete compile task (RuntimeError)
    from /Library/Ruby/Gems/2.0.0/gems/mini_portile-0.6.2/lib/mini_portile.rb:271:in `chdir'
    from /Library/Ruby/Gems/2.0.0/gems/mini_portile-0.6.2/lib/mini_portile.rb:271:in `execute'
    from /Library/Ruby/Gems/2.0.0/gems/mini_portile-0.6.2/lib/mini_portile.rb:70:in `compile'
    from /Library/Ruby/Gems/2.0.0/gems/mini_portile-0.6.2/lib/mini_portile.rb:110:in `cook'
    from extconf.rb:278:in `block in process_recipe'
    from extconf.rb:177:in `tap'
    from extconf.rb:177:in `process_recipe'
    from extconf.rb:475:in `<main>'
ERROR:  Error installing fastlane:
    ERROR: Failed to build gem native extension.

    Building has failed. See above output for more information on the failure.

Gem files will remain installed in /Library/Ruby/Gems/2.0.0/gems/nokogiri-1.6.6.2 for inspection.
Results logged to /Library/Ruby/Gems/2.0.0/gems/nokogiri-1.6.6.2/ext/nokogiri/gem_make.out