With 'zypper info --supplements', I
understood how I got
xdg-desktop-portal-gnome installed.
It is when I manually installed flatpak a few days ago (thus it
has
nothing to do with a 'zypper dup').
Installing flatpak installs xdg-desktop-portal-gnome because of:
Supplements : (gnome-shell and (flatpak or snapd))
In the output of 'zypper info --supplements
xdg-desktop-portal-gnome'.
Thus it is equivalent as if flatpak had xdg-desktop-portal-gnome
as
Recommends.
No, it is not.
How is it different ? As I understand it, "Supplements" is a reverse
"Recommends".
In any case, that "Supplements" causes xdg-desktop-portal-gnome to
be installed when flatpak (or snapd) is installed, as if
xdg-desktop-portal-gnome was a recommend of flatpak.
Hence the question, should flatpak and
snapd install
xdg-desktop-portal-gnome ?
Well ...
- flatpak (and snapd) most certainly needs xdg-desktop-portal.
After all, XDP is created by flatpak. Without it you probably get
rather crippled functionality. So /some/ implementation of XDP
backend has to be present.
- if user is using GNOME, it is just natural to use XDP backend
that integrates into GNOME. The fact that gnome-shell is installed
can be considered as a strong hint that user intends to use GNOME.
So from the distribution point of view this Supplements is pretty
much correct.
The practical problem is that this information is static. Even if
user mostly works with GNOME, user still may log in into different
desktop occasionally. There could be other users using different
desktop. Until recently XDP did not offer any way to influence
which backend gets used. This changed in xdg-dekstop-portal 1.17
where you can disable specific portals or interfaces from these
portals per desktop and also globally or per-user.
https://github.com/flatpak/xdg-desktop-portal/issues/906#issuecomment-1342976355
That said, we still have no idea why xdg-desktop-portal-gnome
fails to start for you. The bug mentioned by Simon was the result
of the wrong configuration (incorrect environment in systemd user
instance). If this happens in your case, there is a bug somewhere
that needs to be fixed. Removing xdg-desktop-portal-gnome just
hides this bug.
Thanks for the elaborate explanation.
xdg-desktop-portal-gnome.service fails to start for me because I run
my system in multi-user.target (not using a Desktop Manager and
using startx) and xdg-desktop-portal-gnome.service depends on
graphical-session.target, resulting in:
I know that not using a Desktop Manager is not recommended and maybe
not supported, so I'm ready to cope with some (rare) caveats like
these.