GNOME Wayland session?

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1

I’m running into a weird thing where GNOME is using X, rather than Wayland, under 19.09 (clean install). I remember under 19.03 that there were two sessions, one for X and one for Wayland. But now I just see one session, and it loads me up in X.

Pocking around a bit, it looks like gnome-session is dropping a gnome.desktop file in both wayland-sessions and xsessions, so I wonder if I’m running into some variant of Ticket #56342 (lePerdu describes something there that sounds like what I’m experiencing). I only see a single session available for GNOME in GDM, and it corresponds to gnome.desktop (the files in wayland-sessions and xsessions are identical).

Anyone else experiencing this? Does anyone know if other distros have duplicate gnome.desktop files in the two session locations?

2

In case anyone else runs into this, here’s what my problem was:

I’m importing <nixpkgs/nixos/modules/profiles/hardened.nix>, and then tweaking a few settings that don’t make sense in a desktop context. It used to be that one of these tweaks was to set security.hideProcessInformation = false, as otherwise this would break GDM. However, in 19.09 hideProcessInformation includes a few tweaks that let GDM work.

But! Having hideProcessInformation set to true still turns out to break a set of other things in subtle ways, including the ability of non-root users to spawn Wayland sessions.

TL;DR Make sure that security.hideProcessInformation = false; if you want GNOME to be able to run a Wayland session.