ERROR: Failed to build gem native extension.

While attempting to install a package from gem, I encountered this issue:

sudo gem install dashing Building native extensions. This could take a while… ERROR: Error installing dashing: ERROR: Failed to build gem native extension. /usr/bin/ruby1.9.1 extconf.rb /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require’: cannot load such file — mkmf (LoadError) from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require’ from extconf.rb:2:in `’ Gem files […]