Bug#1051004: elpa-exwm: please provide an exwm-portals.conf for xdg-desktop-portal

[Simon McVittie <smcv@debian.org>]

Package: elpa-exwm
Severity: normal
Tags: trixie sid
User: xdg-desktop-portal@packages.debian.org
Usertags: portals.conf

xdg-desktop-portal 1.17.x introduces a new way to select which portals will
be used for which desktop environments, modelled on mimeapps.list:

- each desktop environment should provide a file like
  /usr/share/xdg-desktop-portal/exwm-portals.conf

- the filename is ${DESKTOP}-portals.conf where ${DESKTOP} is the desktop
  environment's entry in $XDG_CURRENT_DESKTOP (the same as the DesktopNames
  from /usr/share/{x,wayland-}sessions/*.desktop), folded to lower case

- sysadmins and users can override this via files named portals.conf or
  ${DESKTOP}-portals.conf in various locations like /etc/xdg-desktop-portal
  and ~/.config/xdg-desktop-portal

Please see portals.conf(5) or its source code
https://github.com/flatpak/xdg-desktop-portal/blob/main/doc/portals-conf.rst
for full details.

elpa-exwm sets XDG_CURRENT_DESKTOP=EXWM, so it should provide an
exwm-portals.conf that sets up the correct portal backends.  For example,
if the intention is to use x-d-p-gtk for desktop interfaces such as
File->Open and File->Save As... dialogs, then the simplest way to write
that would be:

[preferred]
default=gtk;

Thanks,
    smcv

-- 
This is part of a mass bug filing:
https://lists.debian.org/debian-devel/2023/08/msg00311.html