dbind, failed to connect to socket, permission denied, using Lightdm socket

[Massimo-B]

Coming from https://forums.gentoo.org/viewtopic-t-1172784.html we encountered a severe issue starting evolution, and can't find out where to file this issue upstream: evolution, lightdm, webkit-gtk, at-spi2-core

(evolution-alarm-notify:8420): dbind-WARNING **: 09:24:15.592: Couldn't connect to accessibility bus: Failed to connect to socket /run/user/134/at-spi/bus_0: Permission denied

at-spi curiously takes the socket from lightdm instead of the local user and fails because of permissions.

The only correlation for all affected users is, that we all use lightdm. But lightdm was not updated and thus did not introduce the issue.

The gdbus call in evolution comes from webkit-gtk, which was updated from 2.44.4-r410 to 2.46.5-r410.

Some users started switching from lightdm to slim which solved the issue for them. Do you have any idea what could be broken?