Re: GDM update!

[Timothy Sample <samplet@ngyro.com>]

Hi Ludo,

Ludovic Courtès <ludo@gnu.org> writes:

> Hello Guix!
>
> I’m happy to report that GDM basically works, including choosing among X
> session… and it has a neat Guix theme!

Woohoo!  I like the background!

I have some changes that are more-or-less ready.  It’s mostly just
cleaning up, but it makes it so that GNOME does not have to be in the
system profile for GDM to work.  (Note that the GDM service references
GNOME Shell, which requires most of GNOME, but it doesn’t end up in the
profile.)

I spent some time trying to get “libgdm” split out from GDM, but GNOME
Shell kept getting killed with SIGTRAP.  This happens during the
execution of JavaScript code, and the recommended way to get a backtrace
did not work, so I’m stuck there.

I will try and send patches in the next day or two.

> The one thing I didn’t get to work is ~/.xsession support.  Any ideas?

Digging around in the source code, there’s a comment that says that the
distributed “Xsession” script should run “~/.xsession” if passed the
special keyword “custom”.  However, looking at the actual script
suggests that this comment is mistaken.  (If it did work, you might be
able to make a “custom.desktop” file with “Exec=custom” that would
trigger the right behaviour.  I did not test this.)

Debian provides a custom “Xsession” script and a custom
“default.desktop” file, which runs the script with the special argument
“default”.  With this argument, the “Xsession” does a bunch of stuff by
running all of the scripts in an “Xsession.d” directory, including one
that tries running “~/.xsession”.

In short, it looks like we have to either fix or customize the
“Xsession” script.  Making the script work like the comment suggests and
using “custom.desktop” is probably the simplest thing to do.

> I’d real like to get that fixed and then we can finally replace SLiM
> with GDM as the default.
>
> BTW, at the Guix Days, there were discussions about defaulting to
> LightDM instead of GDM.  I forgot to mention then that using LightDM
> wouldn’t solve the GNOME use case; in particular, closing the lid under
> GNOME wouldn’t lock the screen, and clicking the lock button wouldn’t
> have any effect, which is pretty bad.

Of course, it is good to have a nice alternative to SLiM that is simpler
than GDM.  GDM is needed for the proper GNOME experience, but it is too
much for most non-GNOME setups.  Ultimately, Guix is nice and
configurable, so I’m everyone can find a way to be happy.  :)


-- Tim