On 2018-06-12 08:21 +0300, Eli Zaretskii wrote:
> Ugh, macOS...  This means no xbacktrace and no other GDB
> wizardry...

Indeed.

> Well, I think the most important thing is to produce a Lisp
> backtrace from the error.

Turns out 26.1 cannot load a version of python.el (by dave love) that I
have in my site-lisp.

1. emacs -Q -l python.el
2. M-x python-mode

,----[ error ]
| Variable binding depth exceeds max-specpdl-size
| Error in post-command-hook (global-eldoc-mode-check-buffers): (error "Variable binding depth exceeds max-specpdl-size")
`----

Gnus was just loading python-mode to fontify some code in an article.