Re: New "gnus-search" syntax and interface

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Eric S Fraga <e.fraga@ucl.ac.uk> writes:

> On Friday, 13 Nov 2020 at 08:15, Eric Abrahamsen wrote:
>> Bummer, I'm sorry about this. 
>
> Don't worry!  It's only a minor inconvenience as I can still use
> "in-group" searches/filtering.
>
>> Can you show me your server config, which I assume looks like:
>>
>> '(nnml "" (nnir-search-engine notmuch (<maybe more config>)))
>
> I do have:
>
> '(nnml "outlook" (nnir-search-engine notmuch) (get-new-mail t))

Okay, simple enough.

> and I used to have:
>
>   (setq nnir-notmuch-filter-group-names-function nil)
>
> but I've deleted that for the moment with no effect (restarting emacs &
> gnus).

That used to be nil by default, so it would only come into play if you'd
set it to something.

> Can you tell me the minimal settings I need to get nnml groups searched
> with notmuch?  My server setup is in need of a deep clean so this is a
> good excuse.

The cleanest thing to do is probably keep all the config in the server
definition itself. So:

'(nnml "outlook"
       (gnus-search-engine
	gnus-search-notmuch
	(remove-prefix "/path/to/mail/toplevel/")
	(config-file "/path/to/notmuch/config")))

If you anticipate switching back to Emacs 27 you can keep using
'(nnir-search-engine notmuch), that will continue to be honored.

If you feel like the searches are being conducted correctly, then my
guess is that the 'remove-prefix is wrong, and Gnus is parsing notmuch's
output incorrectly.

Did you customize `nnir-notmuch-remove-prefix'? I also note that its
default value is:

(regexp-quote (or (getenv "MAILDIR") (expand-file-name "~/Mail")))

While the default value of the equivalent
`gnus-search-notmuch-remove-prefix' is:

(concat (getenv "HOME") "/Mail/")

I'm not sure why I did that differently (though on my machine the result
is the same). Can you try the config above (with the 'remove-prefix
clause) and confirm that the path in that clause really is the path to
the toplevel directory of your mail installation? Basically, removing
the 'remove-prefix should result in a relative file path where the
directory is the group name.

That's my first and best guess.

Eric