gnus registry takes 21 seconds to save and I can't prune it

[hobbes@poukram.net (Rémi Letot)]

Hello,

I have noticed quite a few slowdowns in my emacs for some times, but it
never became annoying enough for me to investigate.

Until now :-)

Starting emacs, gnus, or quitting them has become annoyingly long. It is
not really problematic because I leave emacs/gnus on for weeks at a
time, but still. Besides, pressing s in the group buffer is far too long
to be comfortable.

So, I diagnosed it to gnus-registry-save taking 21 seconds. 

I tried to see what happens in there, and noticed that I could set
gnus-registry-max-entries to a sensible number, but then I get an error
whenever I try to prune the registry (meaning as soon as I try to do
anything in gnus).

The error is "cl-some: Wrong type argument: listp, quote".

That happens in registry-collect-prune-candidates, on the "(memq (car
entry-key) precious)))" line, but there stops my lisp and edebug foo.

In short: can anyone help ? :-)
-- 
Rémi