LightDM - Apr 2020 - how is start-default-seat supposed to work?

Hi,

I would like to have lightdm only run on seat-1, and not seat0.
I am running debian testing, with lightdm 1.26.0-7.

Based on the description of the start-default-seat option in
data/lightdm.conf, i.e.:

# start-default-seat = True to always start one seat if none are defined in the
configuration

I expected that setting this option to false would mean that a seat
would only be started in lightdm if there were specific config lines
for that seat.  So generic [Seat:*] configs would not be considered
for purposes of whether to start a specific seat; to start on seat0,
you would need some config lines under [Seat:seat0], and likewise in
order to start on seat-1, you would need some config lines under
[Seat:seat-1].

However, that did not work, and looking at the code in src/lightdm.c,
it appears that setting start-default-seat=false, lightdm never starts
any seats.

To achieve my goal, I could imagine fixing start-default-seat to work
like I expect, as it does not seem at all useful currently, or adding
a new seat section config option to inhibit starting a seat.  Please
let me know what you think of these options.

thanks,
Greg

> I would like to have lightdm only run on seat-1, and not seat0.
> I am running debian testing, with lightdm 1.26.0-7.
Why do you want to do this?  The solution will be different depending
on whether you only want one seat forever, or whether you want to
retain the ability to start the other seat as needed.

I guess start-default-seat is to handle the default configuration where
no specific seat is configured, but you still want to bring up seat0.
> So generic [Seat:*] configs would not be considered
> for purposes of whether to start a specific seat; to start on seat0,
> you would need some config lines under [Seat:seat0], and likewise in
> order to start on seat-1, you would need some config lines under
> [Seat:seat-1].
> 
> However, that did not work
Did you fix the problem from your other thread that was preventing X
from starting as seat-1 due to the lack of a suitable display device?
Possibly that is why it did not work.

Cheers,
Adam.