Registry save: apparently circular structure being printed

[Bob Newell <bobnewell@bobnewell.net>]

I came across something that undoubtedly will be hard to reproduce ---
until some ultimately inconvenient moment. I had just set up a half
dozen or so RSS feeds for gnus (using the simple G R method). Now, the
RSS part may or may not be relevant, but I did load a lot of articles
and make a lot of changes to the feeds, killing some, adding some,
etc., for quite a while.

I have code that ensures gnus is properly closed out on exiting Emacs,
and that includes saving the registry (gnus takes care of it on its
own exit, it seems).

At the point of saving the registry, I started getting the message
"Apparently circular structure being printed". This persisted until I
killed emacs directly and deleted the gnus registry. Not exactly an
optimal solution!

I realize this is obscure, and my report is necessarily bare-bones,
but has anyone ever seen anything like this?

In the interim I'm increasing max-lisp-eval-depth from the default 800
to 3000, just before gnus is closed out. I have no idea if this will
be sufficient and will only find out when and if the problem returns.

-- 
Bob Newell
Honolulu, Hawai`i

Via Linux/Emacs/Gnus/BBDB.