> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Tue, 31 Jan 2017 18:07:05 +0000
>
>  (setq byte-compiler-debug t) ?
>
> While there, here's a patch to document this variable:

Thanks, please also document it in the ELisp manual, and push both
changes to emacs-25.