    # File lib/rubygems/commands/unpack_command.rb, line 38
      def execute
        gemname = get_one_gem_name
        path = get_path(gemname, options[:version])

        if path then
          basename = File.basename(path).sub(/\.gem$/, '')
          target_dir = File.expand_path File.join(options[:target], basename)
          FileUtils.mkdir_p target_dir
          Gem::Installer.new(path).unpack target_dir
          say "Unpacked gem: '#{target_dir}'"
        else
          alert_error "Gem '#{gemname}' not installed."
        end
      end