build (Gem::Ext::RakeBuilder)

    # File lib/rubygems/ext/rake_builder.rb, line 12
      def self.build(extension, directory, dest_path, results)
        if File.basename(extension) =~ /mkrf_conf/i then
          cmd = "#{Gem.ruby} #{File.basename extension}"
          cmd << " #{Gem::Command.build_args.join " "}" unless Gem::Command.build_args.empty?
          run cmd, results
        end

        # Deal with possible spaces in the path, e.g. C:/Program Files
        dest_path = '"' + dest_path + '"' if dest_path.include?(' ')

        cmd = ENV['rake'] || "#{Gem.ruby} -rubygems #{Gem.bin_path('rake')}" rescue Gem.default_exec_format % 'rake'
        cmd += " RUBYARCHDIR=#{dest_path} RUBYLIBDIR=#{dest_path}" # ENV is frozen

        run cmd, results

        results
      end