https://www.emacswiki.org/emacs/DebuggingWithEmacs
has a good solution for highlighting current line when debugging.
What it looks like:
Neat! I’m hoping that it can be installed in Emacs core. And there was already a discussion
https://lists.gnu.org/archive/html/help-gnu-emacs/2013-02/msg00056.html
in 2013.
--
Zhiwei Chen