例如：有时候遇到这种错误信息，emacs又没加载完所有插件，很多自己常用keymap都没有生效，这时候找错误就比较别扭。如果能有行号信息，是不是就可以快速找到错误了？请问可以在backtrace里加入行号吗?
Warning (initialization): An error occurred while loading `d:/xxxx/.emacs.d/init.el':
Symbol's value as variable is void: k
To ensure normal operation, you should investigate and remove the
cause of the error in your initialization file. Start Emacs with
the `--debug-init' option to view a complete error backtrace.