Thunderbird snap can access X11 although not plugged (debian 11)

hi,

when I started my debian 11 system i noticed, that the thunderbird snap was suddenly using X11 instead of wayland. I noticed it because I have a xeyes running and it was reacting to the mouse position.

So i checked and disconnected thunderbird from the slot:

$ snap connections thunderbird
...
Interface                 Plug                                  Slot                             Notes
wayland                   thunderbird:wayland                   :wayland                         -
x11                       thunderbird:x11                       -                                -

Restarting thunderbird did not change anything. xeyes still gets the input from thunderbird.

In the end I want to run thunderbird again on wayland, but the more important issue is that the snap should not have been able to communicate with X11. I think this should not happen. I want to prevent the apps from accessing X11.

Thunderbird snap version installed: 102.0.1-2 (228) 105MB -

This is inside a gnome wayland user session.

~$ snap version
snap    2.56.2
snapd   2.56.2
series  16
debian  11
kernel  5.10.0-16-amd64

$ snap connections thunderbird
Interface                 Plug                                  Slot                             Notes
audio-playback            thunderbird:audio-playback            :audio-playback                  -
avahi-observe             thunderbird:avahi-observe             -                                -
browser-support           thunderbird:browser-sandbox           :browser-support                 -
camera                    thunderbird:camera                    -                                -
content[gnome-3-38-2004]  thunderbird:gnome-3-38-2004           gnome-3-38-2004:gnome-3-38-2004  -
content[gtk-3-themes]     thunderbird:gtk-3-themes              gtk-common-themes:gtk-3-themes   -
content[icon-themes]      thunderbird:icon-themes               gtk-common-themes:icon-themes    -
content[sound-themes]     thunderbird:sound-themes              gtk-common-themes:sound-themes   -
cups-control              thunderbird:cups-control              :cups-control                    -
desktop                   thunderbird:desktop                   :desktop                         -
desktop-legacy            thunderbird:desktop-legacy            :desktop-legacy                  -
gpg-keys                  thunderbird:gpg-keys                  -                                -
gsettings                 thunderbird:gsettings                 :gsettings                       -
home                      thunderbird:home                      :home                            -
network                   thunderbird:network                   :network                         -
network-control           thunderbird:network-control           -                                -
opengl                    thunderbird:opengl                    :opengl                          -
removable-media           thunderbird:removable-media           -                                -
system-files              thunderbird:etc-thunderbird-policies  :system-files                    -
u2f-devices               thunderbird:u2f-devices               -                                -
wayland                   thunderbird:wayland                   :wayland                         -
x11                       thunderbird:x11                       -                                -

bump. Anybody can please advise me where to bring this up? Should i open an issue for debian or snapd?

update: i did put up a bug report against snappy in launchpad but it seems nobody had a look https://bugs.launchpad.net/snappy/+bug/1981576

i later found out that the wayland socket is not linked in the thunderbird snap, so thunderbird falls back to X11

note that i think the correct behaviour without that socket is to crash (which happens on ubuntu)

next step: will put up a bug report against snapd in debian