在mac上安装nokogiri的时候各种报错，终于安装成功一次，备份命令。
➜ ~ sudo gem install nokogiri -- --use-system-libraries --with-iconv-dir=/usr/local/Cellar/libiconv/1.14/ --with-xml2-include=/usr/local/Cellar/libxml2/2.9.2/include/libxml2 --with-xml2-config=/usr/local/Cellar/libxml2/2.9.2/bin/xml2-config --with-xslt-config=/usr/local/Cellar/libxslt/1.1.28/bin/xslt-config
Building native extensions with: '--use-system-libraries --with-iconv-dir=/usr/local/Cellar/libiconv/1.14/ --with-xml2-include=/usr/local/Cellar/libxml2/2.9.2/include/libxml2 --with-xml2-config=/usr/local/Cellar/libxml2/2.9.2/bin/xml2-config --with-xslt-config=/usr/local/Cellar/libxslt/1.1.28/bin/xslt-config'
This could take a while...
Successfully installed nokogiri-1.6.5
Parsing documentation for nokogiri-1.6.5
Installing ri documentation for nokogiri-1.6.5
Done installing documentation for nokogiri after 5 seconds
1 gem installed