On our Mac OSx, if we upgrade to latest Ruby 2.1.5 (or even 2.1.2) then there are high chances that we will face issues installing nokogiri gem. We might face errors like:

ERROR: Failed to build gem native extension.

Following are the steps to resolve these issues on Mac OSx

  1. Install library libxml2 using brew.
brew install libxml2
  1. Read complete error dump on console while doing bundle or bundle install. We will notice that there are useful tips to fix this on our OS, for example

for building Nokogiri with a packaged version of libxml2-2.9.2, execute this command on your console

bundle config build.nokogiri "--use-system-libraries --with-xml2-include=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/libxml2"

(Basically issue on my PC was due to libxml2)

  1. Additional information in step 2 above helped me.i.e. manually configuring the include path with-xml2-include. Finally try installing nokigiri gem again and if it still shows the errors then follow these steps
gem install nokogiri -- --with-xml2-include=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/libxml2 --use-system-libraries

and

gem install nokogumbo -- --with-xml2-include=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/libxml2 --use-system-libraries

Hope this helps.