I am trying to install capybara-webkit on ubuntu 12.04, but I get this error:
$ gem install capybara-webkit -v '1.0.0'
Building native extensions. This could take a while...
ERROR: Error installing capybara-webkit:
ERROR: Failed to build gem native extension.
/home/samir/.rvm/rubies/ruby-2.1.0/bin/ruby extconf.rb
Command 'qmake -spec linux-g++' not available
Makefile not found
Gem files will remain installed in /home/samir/.rvm/gems/ruby-2.1.0@dcaclab/gems/capybara-webkit-1.0.0 for inspection.
Results logged to /home/samir/.rvm/gems/ruby-2.1.0@dcaclab/extensions/x86-linux/2.1.0/capybara-webkit-1.0.0/gem_make.out
Any idea?