Re: systemd in 3.12

[Bastien Nocera <hadess hadess net>]

On Thu, 2013-11-21 at 11:13 +0100, Frederic Peters wrote:
> Hi all,
>
> We had a page on https://wiki.gnome.org/Systemd listing the places
> where systemd was required (do we want to keep it uptodate?), and
> there's a note in the "Systemd for the user session" feature page[1]
> stating "we still support non-systemd systems".
>
> But I recently noted (due to a missing systemd devel package on my
> end) that there's some intertwining between gnome-session, gnome-
> control-center, and systemd and upower:
>
>  - gnome-session can build with an older upower (< 0.99), and in that
>    case it supports both systemd and consolekit.
>  - gnome-session can build with new upower, and in that case it only
>    supports systemd.

Older UPower was used in the ConsoleKit case to provide suspend and
hibernate. Given that the new UPower has those APIs removed, and that it
uses logind itself, the CK code could grow a dependency on a logind
compatible daemon. That would also make UPower itself work on those
systems.

>  - gnome-control-center cannot be built with older upower.

That's completely expected.

> What could be the plans, now?
>
>  - make gnome-control-center work with both old and new upower

No. That was one of the goals of my work on UPower. We reduced the
amount of code needed in both gnome-control-center, as well as
gnome-settings-daemon and gnome-shell (and removed a dependency on g-s-d
in gnome-shell). I don't want to have to re-add that I wanted to clean
up in the first place.

>  - make gnome-control-center disable some parts when upower is not
>    recent enough

I don't think we want to cripple gnome-control-center when we'd need to
do the same with gnome-settings-daemon and gnome-shell.

>  - make gnome-session support consolekit and recent upower at the same
>    time

That would require a logind compatible daemon on those systems.

>  - remove consolekit support from gnome-session

That seems like the most straight forward option. That'd mean
implementing a logind compatible daemon on systems that used to use
ConsoleKit. Given the state of ConsoleKit, I'd recommend it.

>  - anything else?

I wouldn't remove the "we don't require systemd", but I would add "we
require a logind daemon that implements those methods/signals/properties
in the same way as the upstream logind".

Cheers