bug#66885: 29.1; gnus search with mu always returns empty

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Britt Anderson <britt@b3l.xyz> writes:

> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>
>>
>> The remove-prefix should delete the file path up to the level of the
>> server, meaning that the group/folder name will be read as the first
>> filepath segment _after_ the removal.
>>
>> In theory, if you have multiple mail installations all indexed by mu,
>> and those installations are represented by multiple Gnus backends, it
>> could still work. If each backend was configured with a separate
>> remove-prefix, then it could only extract the results that were relevant
>> to that backend. I don't think that would currently work correctly,
>> though.
>>
>
> Eric, I don't if this helps, but I have kept fiddling around with this.
> I decided to watch the ~gnus-search-mu-remove-prefix~ variable with this
> in my .gnus.el file:
>
> 	(nnmaildir "b3l-archives"
> 		   (directory "/home/britt/.local/share/mail/b3l.xyz/britt/archives")
> 		   (gnus-search-engine gnus-search-mu
> 				       (remove-prefix "/home/britt/.local/share/mail/b3l.xyz/britt/archives")))
>
>
> There is a maildir "y2023" that lives in archives. Using gnus I can read
> the mail in there.
>
> Before I start gnus none of the gnus-* variables are available from C-h
> v.
>
> After I start gnus I can see many of them, but not the gnus-search-*
> variables.
>
> After I go into gnus and try to perform a search on that directory then
> the gnus-search variables become visible. When I do C-h v
> gnus-search-mu-remove-prefix it still shows "/home/britt/Mail" even
> though the remove prefix was set above. Is my syntax bad somehow?

Your syntax is fine! `gnus-search-mu-remove-prefix' is used as a default
value for `gnus-search-mu` engines, if they don't set their own
`remove-prefix' value. Your config above sets that option, so the global
variable will be ignored in this case. Sorry if that was a bit of a
wild goose chase.

Your configuration looks correct (your configuration also reveals an
annoying redundancy in gnus-search, which is that most nnmail
backends have a "directory" value that can and should be used as the
value of remove-prefix).

Basically, if you're seeing "a maildir "y2023" that lives in archives"
as a Gnus group, then this is just a bug in gnus-search's mu handling,
plain and simple.

> Just hoping this may give you an idea where the trouble lies. Still
> working hard to get back to gnus again.

Thanks for keeping at it! Don't lose hope, and I'll try to figure out
what's going on with gnus-search.