Unable to switch to greeter

Question

I'm using LightDM 1.16.5 along with the Awesome window manager on NixOS.

After logging in, I am unable to switch users without first logging out of my current session. The command dm-tool switch-to-greeter has absolutely no effect and gives no output. Same with dm-tool lock.

Another command I tried after searching the Internet:

$ dbus-send --system --type=method_call --print-reply --dest=org.freedesktop.DisplayManager $XDG_SEAT_PATH org.freedesktop.DisplayManager.Seat.SwitchToGreeter
method return sender=:1.2 -> dest=:1.37 reply_serial=2

Here are some XDG-related environment variables:

XDG_VTNR=7
XDG_SESSION_ID=5
XDG_GREETER_DATA_DIR=/var/lib/lightdm-data/myuser
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session1
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
XDG_CONFIG_DIRS=/home/myuser/.nix-profile/etc/xdg:/nix/var/nix/profiles/default/etc/xdg:/run/current-system/sw/etc/xdg
XDG_SESSION_TYPE=x11
XDG_SEAT=seat0
XDG_SESSION_DESKTOP=none + awesome
XDG_DATA_DIRS=/home/myuser/.nix-profile/share:/nix/var/nix/profiles/default/share:/run/current-system/sw/share
XDG_RUNTIME_DIR=/run/user/12345

Can anyone help, please?

Answer 1

Since there doesn't seem to be any knowledge of how to solve this as a user, I've filed a bug report against LightDM at https://bugs.launchpad.net/lightdm/+bug/1531555 and will communicate with the developers there about what might be wrong.