GNOME on Wayland current status

[Rutger Helling]

Hello Guix,

As discussed in patch #29758 I've tried GNOME on Wayland on the
different display managers.

SDDM: Should work, just pick the "GNOME (on Wayland)" session.
SLiM: Doesn't seem to work. I'm not sure if SLiM has support for Wayland
sessions at all.
I couldn't get GDM to start, so I don't know if that works or not.

Note that you can use the following command to manually start GNOME on
Wayland:
XDG_SESSION_TYPE=wayland dbus-run-session gnome-session

This seems to require that you've started GNOME via a display manager
first though.

[Ludovic Courtès]

Hello!

Post by Rutger Helling
As discussed in patch #29758 I've tried GNOME on Wayland on the
different display managers.
SDDM: Should work, just pick the "GNOME (on Wayland)" session.
SLiM: Doesn't seem to work. I'm not sure if SLiM has support for
Wayland sessions at all.
I couldn't get GDM to start, so I don't know if that works or not.
Note that you can use the following command to manually start GNOME on
XDG_SESSION_TYPE=wayland dbus-run-session gnome-session
This seems to require that you've started GNOME via a display manager
first though.

Thanks for the update!

Any idea what could be done in terms of documentation or code
(services?) for people who’d like to try out GNOME on Wayland?

Thanks,
Ludo’.

[Rutger Helling]

Hi Ludo,

I've sent in a patch (#29943) that adds a small paragraph to the
documentation about the current situation.

I believe there was a plan to replace SLiM with GDM for the default
login manager. Getting GDM to work properly should probably be the
first step since it has great Wayland support. From what I know GDM can
default to Wayland and falls back automatically to X11 if for some
reason Wayland doesn't work.

Alternatively we could switch to SDDM as the default for now, until GDM
is ready. That way people are at least able to start a GNOME Wayland
session easily (I don't think this is possible with SLiM). I don't know
how controversial of a change that would be. Note also that unlike GDM,
the SDDM greeter itself still runs on X11 for the time being. Ideally
we want the greeter to run on Wayland too, that
way you can avoid starting a Xorg server running as root.

On Mon, 01 Jan 2018 17:53:14 +0100

Post by Ludovic Courtès
Hello!

Post by Rutger Helling
As discussed in patch #29758 I've tried GNOME on Wayland on the
different display managers.
SDDM: Should work, just pick the "GNOME (on Wayland)" session.
SLiM: Doesn't seem to work. I'm not sure if SLiM has support for
Wayland sessions at all.
I couldn't get GDM to start, so I don't know if that works or not.
Note that you can use the following command to manually start GNOME
XDG_SESSION_TYPE=wayland dbus-run-session gnome-session
This seems to require that you've started GNOME via a display
manager first though.

Thanks for the update!
Any idea what could be done in terms of documentation or code
(services?) for people who’d like to try out GNOME on Wayland?
Thanks,
Ludo’.

[Mark H Weaver]

Hi Rutger,

Post by Rutger Helling
I've sent in a patch (#29943) that adds a small paragraph to the
documentation about the current situation.
I believe there was a plan to replace SLiM with GDM for the default
login manager. Getting GDM to work properly should probably be the
first step since it has great Wayland support. From what I know GDM can
default to Wayland and falls back automatically to X11 if for some
reason Wayland doesn't work.
Alternatively we could switch to SDDM as the default for now, until GDM
is ready.

I recently switched my x86_64 GuixSD laptop to use SDDM, so I could try
out GNOME on Wayland. It mostly works, but there are still a few
problems:

* Even after logging in, SDDM is still visibly running within
xorg-server on VT 7, while Wayland is running on VT 8. If you switch
back to VT 7, you can see the login screen still there, with the clock
showing the time that you logged in instead of the current time. I'm
not sure if there are security implications to this, but it's
certainly a waste of system resources.

* SDDM is based on Qt, so it substantially increases the closure size of
the system, as well as memory usage since SDDM and Xorg-server
continues to run in another VT during your entire session.

* The "Sound" panel of the GNOME settings is non-functional. Whenever I
try to change anything at all in that panel, it crashes.

* Startup notification for several GNOME programs is broken, e.g. GNOME
Terminal, Files (Nautilus), Videos (Totem), and possibly other. When
I launch any of those programs, although the program immediately
starts up, GNOME Shell doesn't seem to realize this, and for quite
some time the spinner continues to indicate that the application is
starting up, and it doesn't show up in the Alt-Tab application
switcher. If you switch to another application, you cannot switch
back to it via Alt-Tab.

* As far as I know, we haven't yet themed SDDM to include our beautiful
GuixSD login screen artwork. It would be a shame to lose that by
default.

On the other hand, I'm pleased to report that under Wayland, tearing no
longer occurs during video playback, scrolling, etc.

Anyway, it's very exciting to see progress on this, but I'm reluctant to
bring Qt into our default system closure, and furthermore I'd be
inclined to wait until more of the aforementioned problems are
addressed.

What do you think?

Mark

[ng0]

Post by Mark H Weaver
Hi Rutger,

Post by Rutger Helling
I've sent in a patch (#29943) that adds a small paragraph to the
documentation about the current situation.
I believe there was a plan to replace SLiM with GDM for the default
login manager. Getting GDM to work properly should probably be the
first step since it has great Wayland support. From what I know GDM can
default to Wayland and falls back automatically to X11 if for some
reason Wayland doesn't work.
Alternatively we could switch to SDDM as the default for now, until GDM
is ready.

What about lightdm? Does it not offer wayland support?
We have no service for it yet, but as far as I understand the greeters
(like 'lightdm-gtk-greeter') writing your own theme is relatively standardized.

Post by Mark H Weaver
I recently switched my x86_64 GuixSD laptop to use SDDM, so I could try
out GNOME on Wayland. It mostly works, but there are still a few
* Even after logging in, SDDM is still visibly running within
xorg-server on VT 7, while Wayland is running on VT 8. If you switch
back to VT 7, you can see the login screen still there, with the clock
showing the time that you logged in instead of the current time. I'm
not sure if there are security implications to this, but it's
certainly a waste of system resources.
* SDDM is based on Qt, so it substantially increases the closure size of
the system, as well as memory usage since SDDM and Xorg-server
continues to run in another VT during your entire session.
* The "Sound" panel of the GNOME settings is non-functional. Whenever I
try to change anything at all in that panel, it crashes.
* Startup notification for several GNOME programs is broken, e.g. GNOME
Terminal, Files (Nautilus), Videos (Totem), and possibly other. When
I launch any of those programs, although the program immediately
starts up, GNOME Shell doesn't seem to realize this, and for quite
some time the spinner continues to indicate that the application is
starting up, and it doesn't show up in the Alt-Tab application
switcher. If you switch to another application, you cannot switch
back to it via Alt-Tab.
* As far as I know, we haven't yet themed SDDM to include our beautiful
GuixSD login screen artwork. It would be a shame to lose that by
default.
On the other hand, I'm pleased to report that under Wayland, tearing no
longer occurs during video playback, scrolling, etc.
Anyway, it's very exciting to see progress on this, but I'm reluctant to
bring Qt into our default system closure, and furthermore I'd be
inclined to wait until more of the aforementioned problems are
addressed.
What do you think?
Mark

[Rutger Helling]

Hi ng0,

that might be a good idea. I was disturbed to learn that SLiM
has seemingly been abandoned since 2013
(source: https://wiki.archlinux.org/index.php/SLiM), so lightdm might
be a good light-weight alternative as the default display manager. Do
you know if the lightdm process itself can run on Wayland (like GDM)?

@Mark

SDDM for the moment cannot run on Wayland yet, which is why it starts
its own X server.

I don't think I've had some of the problems you had with GNOME. Could
you try logging in once via a display manager to GNOME (either X11 or
Wayland is fine), then logging out, stopping the display manager and
running the following command on a TTY:

XDG_SESSION_TYPE=wayland dbus-run-session gnome-session

One of the problems I've run into myself is that X11 screen lockers
like xlock don't seem to work. In GNOME GDM is supposed to be the
screen locker I believe, but I don't think that works at the moment.
I'll try and see if there's a simple Wayland-based screen locker we
could use later.

On Thu, 4 Jan 2018 08:38:58 +0000

Post by ng0

Post by Mark H Weaver
Hi Rutger,

Post by Rutger Helling
I've sent in a patch (#29943) that adds a small paragraph to the
documentation about the current situation.
I believe there was a plan to replace SLiM with GDM for the
default login manager. Getting GDM to work properly should
probably be the first step since it has great Wayland support.
From what I know GDM can default to Wayland and falls back
automatically to X11 if for some reason Wayland doesn't work.
Alternatively we could switch to SDDM as the default for now,
until GDM is ready.

What about lightdm? Does it not offer wayland support?
We have no service for it yet, but as far as I understand the greeters
(like 'lightdm-gtk-greeter') writing your own theme is relatively standardized.

Post by Mark H Weaver
I recently switched my x86_64 GuixSD laptop to use SDDM, so I could
try out GNOME on Wayland. It mostly works, but there are still a
* Even after logging in, SDDM is still visibly running within
xorg-server on VT 7, while Wayland is running on VT 8. If you
switch back to VT 7, you can see the login screen still there, with
the clock showing the time that you logged in instead of the
current time. I'm not sure if there are security implications to
this, but it's certainly a waste of system resources.
* SDDM is based on Qt, so it substantially increases the closure
size of the system, as well as memory usage since SDDM and
Xorg-server continues to run in another VT during your entire
session.
* The "Sound" panel of the GNOME settings is non-functional.
Whenever I try to change anything at all in that panel, it crashes.
* Startup notification for several GNOME programs is broken, e.g.
GNOME Terminal, Files (Nautilus), Videos (Totem), and possibly
other. When I launch any of those programs, although the program
immediately starts up, GNOME Shell doesn't seem to realize this,
and for quite some time the spinner continues to indicate that the
application is starting up, and it doesn't show up in the Alt-Tab
application switcher. If you switch to another application, you
cannot switch back to it via Alt-Tab.
* As far as I know, we haven't yet themed SDDM to include our
beautiful GuixSD login screen artwork. It would be a shame to lose
that by default.
On the other hand, I'm pleased to report that under Wayland,
tearing no longer occurs during video playback, scrolling, etc.
Anyway, it's very exciting to see progress on this, but I'm
reluctant to bring Qt into our default system closure, and
furthermore I'd be inclined to wait until more of the
aforementioned problems are addressed.
What do you think?
Mark

[ng0]

Post by Rutger Helling
Hi ng0,
that might be a good idea. I was disturbed to learn that SLiM
has seemingly been abandoned since 2013
(source: https://wiki.archlinux.org/index.php/SLiM), so lightdm might
be a good light-weight alternative as the default display manager. Do
you know if the lightdm process itself can run on Wayland (like GDM)?

No idea, I've never really used Wayland or Xwayland on any computer other
than my phones. I'd guess the Manual of lightdm would cover this.

Post by Rutger Helling
@Mark
SDDM for the moment cannot run on Wayland yet, which is why it starts
its own X server.
I don't think I've had some of the problems you had with GNOME. Could
you try logging in once via a display manager to GNOME (either X11 or
Wayland is fine), then logging out, stopping the display manager and
XDG_SESSION_TYPE=wayland dbus-run-session gnome-session
One of the problems I've run into myself is that X11 screen lockers
like xlock don't seem to work. In GNOME GDM is supposed to be the
screen locker I believe, but I don't think that works at the moment.
I'll try and see if there's a simple Wayland-based screen locker we
could use later.
On Thu, 4 Jan 2018 08:38:58 +0000

Post by ng0

Post by Mark H Weaver
Hi Rutger,

Post by Rutger Helling
I've sent in a patch (#29943) that adds a small paragraph to the
documentation about the current situation.
I believe there was a plan to replace SLiM with GDM for the
default login manager. Getting GDM to work properly should
probably be the first step since it has great Wayland support.
From what I know GDM can default to Wayland and falls back
automatically to X11 if for some reason Wayland doesn't work.
Alternatively we could switch to SDDM as the default for now,
until GDM is ready.

What about lightdm? Does it not offer wayland support?
We have no service for it yet, but as far as I understand the greeters
(like 'lightdm-gtk-greeter') writing your own theme is relatively standardized.

Post by Mark H Weaver
I recently switched my x86_64 GuixSD laptop to use SDDM, so I could
try out GNOME on Wayland. It mostly works, but there are still a
* Even after logging in, SDDM is still visibly running within
xorg-server on VT 7, while Wayland is running on VT 8. If you
switch back to VT 7, you can see the login screen still there, with
the clock showing the time that you logged in instead of the
current time. I'm not sure if there are security implications to
this, but it's certainly a waste of system resources.
* SDDM is based on Qt, so it substantially increases the closure
size of the system, as well as memory usage since SDDM and
Xorg-server continues to run in another VT during your entire
session.
* The "Sound" panel of the GNOME settings is non-functional.
Whenever I try to change anything at all in that panel, it crashes.
* Startup notification for several GNOME programs is broken, e.g.
GNOME Terminal, Files (Nautilus), Videos (Totem), and possibly
other. When I launch any of those programs, although the program
immediately starts up, GNOME Shell doesn't seem to realize this,
and for quite some time the spinner continues to indicate that the
application is starting up, and it doesn't show up in the Alt-Tab
application switcher. If you switch to another application, you
cannot switch back to it via Alt-Tab.
* As far as I know, we haven't yet themed SDDM to include our
beautiful GuixSD login screen artwork. It would be a shame to lose
that by default.
On the other hand, I'm pleased to report that under Wayland,
tearing no longer occurs during video playback, scrolling, etc.
Anyway, it's very exciting to see progress on this, but I'm
reluctant to bring Qt into our default system closure, and
furthermore I'd be inclined to wait until more of the
aforementioned problems are addressed.
What do you think?
Mark

[Catonano]

Post by ng0

Post by Rutger Helling
Hi ng0,
that might be a good idea. I was disturbed to learn that SLiM
has seemingly been abandoned since 2013
(source: https://wiki.archlinux.org/index.php/SLiM), so lightdm might
be a good light-weight alternative as the default display manager. Do
you know if the lightdm process itself can run on Wayland (like GDM)?

No idea, I've never really used Wayland or Xwayland on any computer other
than my phones. I'd guess the Manual of lightdm would cover this.

This page says: "Supports different display technologies (X, Mir, Wayland
...)."
https://freedesktop.org/wiki/Software/LightDM/

On the Arch wiki there's also a paragraph about migrating from SLIM
https://wiki.archlinux.org/index.php/LightDM#Migrating_from_SLiM

[Mark H Weaver]

Hi Rutger,

Post by Rutger Helling
SDDM for the moment cannot run on Wayland yet, which is why it starts
its own X server.
I don't think I've had some of the problems you had with GNOME. Could
you try logging in once via a display manager to GNOME (either X11 or
Wayland is fine), then logging out, stopping the display manager and
XDG_SESSION_TYPE=wayland dbus-run-session gnome-session

I tried this, and it results in a GNOME-on-wayland session that seems to
work as well as it did when launched via SDDM, but with all of the same
problems I mentioned in my earlier email (except for the resource usage
due to Xorg-server/Qt/SDDM running in another VT).

In particular, the sound setting panel still crashes, and startup
notification is still broken for many GNOME programs including Nautilus
(Files), Totem (Videos), Evince (Documents), and Epiphany (Web).

Additionally, I've noticed that it's not possible to restart GNOME Shell
(via Alt-F2 r) under Wayland. That's not a Guix-specific problem, but
it's a particular problem for Guix because it's needed after updating
one's profile in order to reload the set of known .desktop files, so
that when launching programs via GNOME Shell the updated programs are
run instead of the older ones (which may have security holes).

Post by Rutger Helling
One of the problems I've run into myself is that X11 screen lockers
like xlock don't seem to work. In GNOME GDM is supposed to be the
screen locker I believe, but I don't think that works at the moment.
I'll try and see if there's a simple Wayland-based screen locker we
could use later.

FYI, here are the most recent updates on the efforts to get GDM working
in Guix:

https://lists.gnu.org/archive/html/guix-devel/2017-08/msg00268.html
https://lists.gnu.org/archive/html/guix-devel/2017-10/msg00231.html

Thanks for your work on this!

Regards,
Mark