Error installing nokogiri on AWS

I got the following error when I was deploying a Rails application to AWS:

Installing nokogiri (1.6.2.1)
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.Installing nokogiri (1.6.2.1) 
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

Installing patch on ec2 allows nokogiri to apply patches to libxml2 and libxsd and it will fix the error above.

sudo yum install patch

Note: The installation for nokogiri will take quite some time after this. Be patient.