I try to clone this repo and run bundle install. The bundle process failed and throw this error:
...
Installing nokogiri 1.6.2.1 with na
I had the similar issue. The reason was outdated xcode.
If you run brew doctor you might see it. Just open AppStore, got to updates tab and update your xcode.
What worked for me (on macOS Sierra) was a combination of Sam's answer and the following:
gem install nokogiri -- --with-xml2-include=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include/libxml2 --use-system-libraries
Seems like this is due to nokogiri 1.6.2.1 specific problem.
I add this inside my Gemfile:
gem 'nokogiri', '~> 1.6', '>= 1.6.7'
And run bundle update nokogiri and then bundle. Everything now working fine.