bug#44824: 27.1; Org export as pdf and open file does not open it

["gbiotti@gmail.com" <gbiotti@gmail.com>]

Il 28/01/2021 04:02, Lars Ingebrigtsen ha scritto:
> "gbiotti@gmail.com" <gbiotti@gmail.com> writes:
>
>> The same as using C-c C-e l o
>> "The default PDF program (okular) appears to open (i see the icon, but not
>> the window) and closes without showing anything."
> If I do
>
> $ xdg-open ./doc/lispintro/cons-2.pdf
>
> after `M-x shell', "Document Viewer" is opened as normal.
>
> You don't get any output from xdg-open or anything in the shell buffer?
>
> Glenn Morris <rgm@gnu.org> writes:
>
>> Ref eg https://debbugs.gnu.org/cgi/bugreport.cgi?bug=25234#8
>> https://bugzilla.gnome.org/show_bug.cgi?id=652262
>> https://gitlab.gnome.org/GNOME/glib/-/issues/1208
>> and others going back over a decade.
>> I think Emacs should have a PROBLEMS entry about this.
> Yeah, calling xdg-open (and expecting it not to exit) is a known
> problem, but here it seems that xdg-open doesn't even work from *shell*,
> which is very odd.
>

I have no more ideas.
The problem arise even exporting and opening html, so it's not the file 
type.

Doing a better search I found this:
https://forum.manjaro.org/t/xdg-open-or-kde-open-doesnt-work-when-called-from-emacs/39918

Same problem, but without an answer.

If needed I can make a video of what happen (if so please explain where 
to upload it).