As decided in Gentoo GNOME 2017-02-10 meeting, we need to revert the default session to X11 based for 3.22 stabilization even if USE=wayland is globally set. This is probably just some 3.21 commit(s) revert in gnome-session on gdm or some such. This should be accompanied by an elog/ewarn/einfo/whatever in the ebuild and potentially also some gnome 3.22 upgrade guide mention (just this upgrade guide isn't important enough on this merit to deem a gentoo news item)
Note that the session chosen by a user is saved in AccountsService, which keeps its settings in /var/lib/AccountsService/users/ If testing this change, keep in mind that a user entry will remain there even after creating, removing and re-creating test users of the same name, which means it doesn't reset the chosen session. If user had "gnome" saved before, then this now reverts back to Xorg (while being a wayland session in 3.22 before, but an Xorg session in stable 3.20). If user had "gnome-xorg" saved before (by choosing "GNOME on Xorg" with a previous 3.22 version), then gdm will not find any such session and falls back to "gnome" which will be Xorg too now (but it doesn't reset it in AccountsService until a different session is chosen and GNOME re-chosen in the menu). If user had "gnome-wayland" by explicitly choosing "GNOME on Wayland" on stable 3.20 times, it will remain that, as this session is reintroduced with this bump. commit a62f7893203807969ae4fd725fa3a61e1dc97e65 Author: Mart Raudsepp <leio@gentoo.org> Date: Sat Mar 18 14:22:57 2017 +0200 gnome-base/gnome-session: 3.22.3 bump, revert to Xorg session default, make wayland session be a login shell The upstream bump from 3.22.2 to 3.22.3 just reduces the data traffic for VT switch monitoring. Gentoo-bug: 604110 Backport upstream patch from 3.23.4.1 to re-launch itself as a "bash" login shell when /usr/bin/gnome-session is started for a wayland based session without a login shell. This makes GNOME wayland session to do all the shell setup that a login shell does, which means e.g Gentoo /etc/env.d things get processed via shell profile, fixing all the variable and other setups we rely on heavily in Gentoo. Because this currently re-launches with bash, it will probably only source bash and generic setups, not e.g zsh specific paths. Gentoo-bug: 611146 Forward port upstream patch from 3.19 days that reverted default "gnome" session back to Xorg for 3.20, to do it again in Gentoo 3.22. Also manually forward port translations for the "GNOME on Wayland" string change, where available as a translated string in 3.20. 3.24 should be available faster in Gentoo now, which will get us to Wayland then, as in 3.24 it'll also work with nvidia-drivers and be generally even more mature. Package-Manager: Portage-2.3.4, Repoman-2.3.1
