The upstream session files display managers use have no concept of sessions being composed from
desktop manager and window manager. To be able to set upstream session files as default
session, we need a single option. Having two different ways to set default session would be confusing,
though, so we decided to deprecate the old method.
We also created separate script for each session, just like we already had a separate desktop
file for each one, and started using displayManager.sessionPackages mechanism to make the
session handling more uniform.
There's two ways of providing graphical sessions now:
- `displayManager.session` via. `desktopManager.session` and
`windowManager.session`
- `displayManager.sessionPackages`
`sessionPackages` doesn't make a distinction between desktop and window
managers. This makes selecting a session provided by a package using
`desktopManager.default` nonsensical.
We therefor introduce `displayManager.defaultSession` which can select a session
from either `displayManager.session` or `displayManager.sessionPackages`.
It will default to `desktopManager.default + windowManager.default` as before.
If the dm default is "none" it will select the first provided session from
`sessionPackages`.
Having a default session resulted in GDM not remembering the last used
session.
So do not force the session until setSessionScript is made aware of the
last session used.
A centralized list for these renames is not good because:
- It breaks disabledModules for modules that have a rename defined
- Adding/removing renames for a module means having to find them in the
central file
- Merge conflicts due to multiple people editing the central file
When session debugging was enabled in GNOME but not in Pantheon
{
services.xserver = {
desktopManager.pantheon = {
enable = true;
};
desktopManager.gnome3 = {
enable = true;
debug = true;
};
};
}
it caused a conflict:
error: The option `environment.sessionVariables.GNOME_SESSION_DEBUG' has conflicting definitions, in `<nixpkgs/nixos/modules/services/x11/desktop-managers/pantheon.nix>' and `<nixpkgs/nixos/modules/services/x11/desktop-managers/gnome3.nix>'.
Unfortunately, you can't configure the default user-session
with GDM like lightdm. I've opened a feature request [0]
but I'd like to be able to do this now.
We use a GObject Python script using bindings to AccountsService
to achieve this. I'm hoping the reliable heuristic for session names
is the file's basename. We also have some special logic for which
method to use to set the default session. It seems set_x_session is
deprecated, and thusly the XSession key, but if that method isn't used
when it's an xsession it won't be the default in GDM.
[0]: https://gitlab.gnome.org/GNOME/gdm/issues/535
The SLIM project is abandoned and their last release was in 2013.
Because of this it poses a security risk to systems, no one is working
on it or picked up maintenance. It also lacks compatibility with systemd
and logind sessions. For users, there liikely isn't anything like slim
that's as lightweight in terms of dependencies.
When we did the revert of adding gnome-flashback to systemd.packages [0]
I forgot to test with other display managers. If we use GDM with gnome-flashback
it appears it doesn't try to fallback to non-systemd startup and always fails and
starts the regular gnome-session. So adding gnome-flashback to systemd.packages
was perfectly fine, but we did forgot one detail. We need systemd targets for the
customSessions which is added using mkSystemdTargetForWm in the gnome-
flashback package.
[0]: 42f567b30d
Instead of assign the libinput options to touchpad devices only, it
should be appied by any device using libinput.
Due to the fact that `40-libinput.conf` already defines libinput as
driver for any detected input device, we can use `MatchDriver` to appy
options.
I've noticed a similar issue in Pantheon, without this
sound theme installed there's no system sounds.
I believe it's because the gnome theme and the pantheon
theme inherit this one.
This reverts commit 60aedadc59.
Using tests from #71212 I am now unable to reproduce there being issues
with starting the default metacity flashback session without this.
