rails bundle error - capybara-webkit - Failed to build native extension

Question

trying to run bundle (existing app, new machine running Ubuntu 12.04).

Installing capybara-webkit (0.12.1) with native extensions 
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

        /home/durrantm/.rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb 


Gem files will remain installed in /home/durrantm/.rvm/gems/ruby-1.9.3-p194@dmstaffing/gems/capybara-webkit-0.12.1 for inspection.
Results logged to /home/durrantm/.rvm/gems/ruby-1.9.3-p194@dmstaffing/gems/capybara-webkit-0.12.1/./gem_make.out
An error occurred while installing capybara-webkit (0.12.1), and Bundler cannot continue.
Make sure that `gem install capybara-webkit -v '0.12.1'` succeeds before bundling.

Answer 1

The answer was "qt" -:

sudo apt-get install libqt4-dev libqtwebkit-dev