bug#63842: 30.0.50; Slow 'gnus-summary-refer-thread'

[Manuel Giraud via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Andrew Cohen <cohen@bu.edu> writes:

[...]

> Can you tell me (for circumstances where the referral is slow):

Hi Andrew,

> 1. What kind of group and the backend used  in the group from which you
> did the referral (imap, nntp, etc)

I'm retrieving my mail via IMAP into a local nnml backend.  This is in
such group that I witness the slowdown.  I have not tested on any other
backend.

> 2. What search engine are you using (imap, notmuch, etc)

I have setup notmuch onto the default nnml directory and set
'gnus-select-method' as follow:
--8<---------------cut here---------------start------------->8---
(setq gnus-select-method '(nnml "" (gnus-search-engine gnus-search-notmuch)))
--8<---------------cut here---------------end--------------->8---

> 3. When the thread referral happens which groups are getting searched?
> (In particular, what is the value of
> 'gnus-refer-thread-use-search? And is the search on the full server or
> is it restricted to a single group?). And can you tell if the same set of
> groups is being searched before and after the slowdown appeared?

I have let 'gnus-refer-thread-use-search' to its default NIL value.  My
search was restricted to a single (mail) group and, previously, I was
doing the same thread referral search on the same group.

Thanks and hope this helps.
-- 
Manuel Giraud