# File lib/bundler/dsl.rb, line 28
    def eval_gemfile(gemfile, contents = nil)
      contents ||= Bundler.read_file(gemfile.to_s)
      instance_eval(contents, gemfile.to_s, 1)
    rescue SyntaxError => e
      bt = e.message.split("\n")[1..-1]
      raise GemfileError, ["Gemfile syntax error:", *bt].join("\n")
    rescue ScriptError, RegexpError, NameError, ArgumentError => e
      e.backtrace[0] = "#{e.backtrace[0]}: #{e.message} (#{e.class})"
      Bundler.ui.warn e.backtrace.join("\n       ")
      raise GemfileError, "There was an error in your Gemfile," \
        " and Bundler cannot continue."
    end