# File lib/chef/knife/solo_cook.rb, line 113
      def validate!
        validate_ssh_options!

        if File.exist? 'solo.rb'
          ui.warn "solo.rb found, but since knife-solo v0.3.0 it is not used any more"
          ui.warn "Please read the upgrade instructions: https://github.com/matschaffer/knife-solo/wiki/Upgrading-to-0.3.0"
        end
      end