install_gem.rb

      def run
        command = "gem install #{gemspec_helper.gem_path}"
        output.puts "Executing #{command.inspect}:"

        sh sudo_wrapper(command) # TODO where does sh actually come from!? - rake, apparently
      end

      def sudo_wrapper(command)
        if use_sudo?
          "sudo #{command}"
        else
          command
        end
      end

      def use_sudo?
        if host_os =~ /mswin|windows|cygwin/i
          false
        else
          true
        end
        
      end

      def host_os
        Config::CONFIG['host_os']
      end