Michael Albinus <michael.albinus@gmx.de> writes:

> Thierry Volpiatto <thievol@posteo.net> writes:
>
>>> Hi Michael,
>
> Hi Thierry,
>
>> More exactly, it seems gio command is correctly extracted in
>> `tramp-sh-handle-file-notify-add-watch` with
>> (tramp-get-remote-gio-monitor v) but later in the process filter
>> (tramp-connection-property-p proc "gio-file-monitor") returns nil.
>
> Does the appended patch fixes this?

Partially. No more error but the watcher have no effect like on
emacs-27.
helm-find-files is caching the directories it visits and for each
directory is adding a watcher, for example on emacs-27:

M-x helm-find-files => navigate to /sudo::/home/me/tmp/ directory:

foo.txt
bar.txt
baz.txt

Now from a shell:

touch ~/tmp/test.txt

M-x helm-find-files => navigate to /sudo::/home/me/tmp/ directory:

foo.txt
bar.txt
baz.txt
test.txt

test.txt is not added with emacs-28, that's mean the watcher didn't
notify helm to remove tmp directory from cache.

Thanks.

-- 
Thierry