bug#73859: [PATCH 0/2] lightdm: Fix empty session list.

[Dariqq]

This changes lightdm and the service to use the config file from a well-known 
location in /etc/lightdm/lightdm.conf s.t. the gtk-greeter knows about our 
custom "sessions-directory".

I then removed the custom config file from the lightdm servcice and removed 
passing XDG_CONFIG_DIRS which are no longer neccesary.

Renamed lightdm-configuration->greeters-config-dir to just 
lightdm-configuration-directory (inspired by how the dbus-service names its 
directory) and also moved the etc-extension into a seperate procedure for 
consistency with other services.


I tested this on my i686 pc and ran 'make check-system TESTS=lightdm' 
successfully


This is also the approach done on NixOS, see

* 
https://github.com/NixOS/nixpkgs/blob/nixos-unstable/pkgs/applications/display-managers/lightdm/default.nix#L93
*https://github.com/NixOS/nixpkgs/blob/nixos-unstable/nixos/modules/services/x11/display-managers/lightdm.nix#L259

Fixes https://issues.guix.gnu.org/68055


Dariqq (2):
  gnu: lightdm: Use global sysconfdir.
  gnu: lightdm-service-type: Add lightdm.conf to /etc/lightdm.

 gnu/packages/display-managers.scm |  7 ++++-
 gnu/services/lightdm.scm          | 48 ++++++++++++++-----------------
 2 files changed, 27 insertions(+), 28 deletions(-)


base-commit: ea11d3608566174c4bae70faa4f9d0c67748d2db
-- 
2.46.0