我正在尝试使用以下方法安装Nokogiri：
sudo gem install nokogiri
这是安装后的混乱：
Building native extensions. This could take a while...
ERROR: Error installing nokogiri:
ERROR: Failed to build gem native extension.
/Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/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/micahsherman/.rvm/gems/ruby-1.9.3-p429/gems/nokogiri-1.6.0/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... OK
Running 'compile' for libxslt 1.1.26... OK
Running 'install' for libxslt 1.1.26... OK
Activating libxslt 1.1.26 (from /Users/micahsherman/.rvm/gems/ruby-1.9.3-p429/gems/nokogiri-1.6.0/ports/x86_64-apple-darwin13.0.0/libxslt/1.1.26)...
checking for libxml/parser.h... *** 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/micahsherman/.rvm/rubies/ruby-1.9.3-p429/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
--with-libxslt-config
--without-libxslt-config
--with-pkg-config
--without-pkg-config
--with-libxml-2.0-config
--without-libxml-2.0-config
--with-libiconv-config
--without-libiconv-config
/Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:506:in `try_cpp'
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:970:in `block in find_header'
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:790:in `block in checking_for'
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:284:in `block (2 levels) in postpone'
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:284:in `block in postpone'
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:280:in `postpone'
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:789:in `checking_for'
from /Users/micahsherman/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/mkmf.rb:969:in `find_header'
from extconf.rb:166:in `<main>'
Gem files will remain installed in /Users/micahsherman/.rvm/gems/ruby-1.9.3-p429/gems/nokogiri-1.6.0 for inspection.
Results logged to /Users/micahsherman/.rvm/gems/ruby-1.9.3-p429/gems/nokogiri-1.6.0/ext/nokogiri/gem_make.out
我将不胜感激一些提示或建议。 我正在使用Ruby 1.9.4，Rails 3.2.13，我不知道为什么这不起作用。 我正在使用小牛队，我认为这可能是问题所在。
我已经更新了 xcode 等。
这不是一个直接的解决方案，而是让你朝着正确的方向前进。 rvm在解决自己的问题方面非常扎实。请按照以下步骤操作，帮助rvm发挥其魔力
运行rvm requirements以查找缺少的内容。
使用rvm pkg（在旧版本的 RVM 上）或rvm autolibs安装缺少的包。
确保您阅读了在此过程中要求您阅读的所有文档rvm。
成功完成后，请尝试安装 nokogiri 。