Login option 'GNOME on Wayland' does not start from LightDM

[Fred]

When picking GNOME on Wayland as session and attempting to login from LightDM then it fails, all you see is a black screen with a blinking cursor.

However, manually running:
$ dbus-run-session gnome-shell --display-server --wayland
from the console/vt1 (Ctrl+Alt+F1) seems to work.
But from LightDM it does not work.

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: gnome-session-wayland 3.20.2-1ubuntu7
ProcVersionSignature: Ubuntu 4.8.0-22.24-generic 4.8.0
Uname: Linux 4.8.0-22-generic x86_64
ApportVersion: 2.20.3-0ubuntu8
Architecture: amd64
Date: Wed Oct 12 18:06:13 2016
InstallationDate: Installed on 2013-12-26 (1020 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
SourcePackage: gnome-session
UpgradeStatus: No upgrade log present (probably fresh install)

[Robert Ancell (robert-ancell)]

Can you attach the contents of /var/log/lightdm/lightdm.log after attempting to start the session? Thanks.

[Fred (eldmannen+launchpad)]

Requested log file attached.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[BigcityCat (pshomeexpress)]

Keeping Unity-Gtreeter is a great way to keep the Ubuntu in gnome3. The importance should be high.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Fred (eldmannen+launchpad)]

I no longer experience this issue.
I can login to my Wayland session now.

However, I do have a related issue where I cannot login to Wayland as guest.

[jhony duenas (jjdd1211)]

Fred, How did you fix it?

On Wed, Apr 19, 2017 at 9:28 AM, Fred <email address hidden> wrote:

> I no longer experience this issue.
> I can login to my Wayland session now.
>
> However, I do have a related issue where I cannot login to Wayland as
> guest.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1632772
>
> Title:
> GNOME on Wayland does not start from LightDM
>
> Status in Ubuntu GNOME:
> Confirmed
> Status in gnome-session package in Ubuntu:
> Confirmed
> Status in lightdm package in Ubuntu:
> Confirmed
>
> Bug description:
> When picking GNOME on Wayland as session and attempting to login from
> LightDM then it fails, all you see is a black screen with a blinking
> cursor.
>
> However, manually running:
> $ dbus-run-session gnome-shell --display-server --wayland
> from the console/vt1 (Ctrl+Alt+F1) seems to work.
> But from LightDM it does not work.
>
> ProblemType: Bug
> DistroRelease: Ubuntu 16.10
> Package: gnome-session-wayland 3.20.2-1ubuntu7
> ProcVersionSignature: Ubuntu 4.8.0-22.24-generic 4.8.0
> Uname: Linux 4.8.0-22-generic x86_64
> ApportVersion: 2.20.3-0ubuntu8
> Architecture: amd64
> Date: Wed Oct 12 18:06:13 2016
> InstallationDate: Installed on 2013-12-26 (1020 days ago)
> InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64
> (20131016.1)
> SourcePackage: gnome-session
> UpgradeStatus: No upgrade log present (probably fresh install)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/ubuntu-gnome/+bug/1632772/+subscriptions
>

[Fred (eldmannen+launchpad)]

@johny, I don't recall having done anything to fix it.
I think it just resolved itself by some package update or something.
Logging into GNOME on Wayland from LightDM as my user works now.
But as guest it doesn't work still.

[willmo (willmo)]

It looks like the bug is actually in unity8-desktop-session. It installs /usr/share/lightdm/lightdm.conf.d/45-unity8.conf, which sets session-wrapper=lightdm-unity8-session, which means lightdm-unity8-session is run in order to start *any* session. lightdm-unity8-session is a shell script that's also part of unity8-desktop-session, and looking at its contents, it appears to be buggy because it assumes that any session that doesn't use X (such as Wayland) is Unity 8 and should run upstart instead of lightdm-session.

I was able to work around this by creating a file /etc/lightdm/lightdm.conf.d/00-willmo.conf with contents

[Seat:*]
session-wrapper=lightdm-session

This overrides the offending setting in 45-unity8.conf and sets session-wrapper back to the default, avoiding the Unity 8 assumptions in lightdm-unity8-session. After rebooting, Wayland sessions now work for me.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Daniel van Vugt (vanvugt)]

Confirmed, thanks willmo. The simple fix for zesty and artful is:

$ sudo apt remove unity8-desktop-session
$ sudo apt autoremove

[Daniel van Vugt (vanvugt)]

ubuntu-meta (1.380) artful; urgency=medium

  * update.cfg; zesty -> artful
  * Refreshed dependencies
  * Removed unity8-desktop-session from desktop-recommends [amd64 arm64
    armhf i386 ppc64el]

 -- Dimitri John Ledkov <email address hidden> Sun, 23 Apr 2017 15:03:58 +0100

[Dimitri John Ledkov (xnox)]

unintentional fix =))))

however, my upload I think is now causing a mess with components mismatches.

[Dimitri John Ledkov (xnox)]

Note, we cannot just remove unity8-desktop-session in zesty, thus some other workaround needed, if we want to SRU this change.

[Daniel van Vugt (vanvugt)]

I think zesty is fine unfixed. If anyone wants a quick fix in zesty then see the previous comments.

[Oliver Grawert (ogra)]

note that i see the non-starting wayland session on a 16.04 system that does not have the unity8-desktop-session package installed, x11 gnome as well as unity (7) start just fine and there is no trace of any unity8 packages on this laptop.

[Jeremy Bícha (jbicha)]

The ubuntu-meta change was a workaround, not a fix, and it doesn't do us any good for Ubuntu Stable Releases so I'm reopening this bug.

[BigcityCat (pshomeexpress)]

I implemented willmo's fix and I also removed unity 8 desktop. It does login into Wayland after applying these workarounds but logout is broken. You can't logout. Juts gets stuck on a blank screen.

[fcole90 (fcole90)]

Using 16.04 I can still reproduce the bug. I don't have any trace of unity8 as well.

[Jeremy Bícha (jbicha)]

fcole90, please file a new bug for your issue.

[fcole90 (fcole90)]

Ok, mine is 1695872

[monkeydri (monkeydri)]

I can successfully login with lightdm after deleting every Xorg session entries correpsonding to a wayland session entry (ex rm /usr/share/xessions/gnome /usr/share/xessions/ubuntu and leave /usr/share/wayland-sessions/gnome and /usr/share/wayland-sessions/ubuntu).