On Sat, 13 Dec 2025 at 17:05:07 +0100, Yves-Alexis Perez wrote:
On Sat, 2025-12-13 at 14:51 +0000, Mike Gabriel wrote:
> I'm actually unsure if it will try to start the daemon itself but I don't
> think so, so at first let's not depend on dbus-daemon.
LightDM exposes itself on system DBus, and it will probably fail to
start if it cannot do that. So, system DBus must be running before
LightDM can see to its business...
I guess that's what default-dbus-system-bus | dbus-system-bus is for.
Yes, for example gdm3 has a similar dependency for the same reason.
As I understand it it doesn't *start* the daemon itself.
The reason I mentioned that possibility is that gdm's "greeter" (login
prompt UI) is implemented by starting a miniature GNOME session to have
somewhere to put accessibility tools and so on, and as part of that, it
explicitly runs `dbus-daemon --session` (or at least it did until
recently, I think v49 relies on `systemd --user` instead). This is a
session bus, not the system bus - same executable, different behaviour.
As implemented in gdm, this specifically needed the reference dbus-daemon
and not some other implementation, because only the reference
dbus-daemon provides /usr/bin/dbus-daemon.
If lightdm has a similar behaviour for its greeter then it might need a
dependency on the dbus-daemon package in order to be able to do that.
But, if you don't know that it does, then it probably doesn't.
smcv
