Crash, black screen with lightdm

[dino99]

Got a crash when lightdm is selected, but apport warns about a non ubuntu package:

unity-settings-daemon (15.04.1+17.10.20171003-0ubuntu1) artful; urgency=medium

  * XSettings: under unity use com.ubuntu.user-interface.desktop keys
    for scaling settings

 -- Marco Trevisan (Treviño) <[e-mail]> Tue, 03 Oct 2017 06:05:23 +0000

so i'm joining the crasfh file

This happen now with each cold boot: get a black screen, does not even get a login screen (using lightdm), so startx is ran from a console to finally get the gnome-shell loaded.
---
ApportVersion: 2.20.7-0ubuntu3
Architecture: amd64
CurrentDesktop: GNOME
DistroRelease: Ubuntu 17.10
EcryptfsInUse: Yes
Package: unity-settings-daemon 15.04.1+17.10.20171003-0ubuntu1
PackageArchitecture: amd64
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 4.13.0-15.16-generic 4.13.4
Tags: artful
Uname: Linux 4.13.0-15-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True

[dino99 (9d9)]

apport information

[dino99 (9d9)]

apport information

[dino99 (9d9)]

apport information

[dino99 (9d9)]

When gdm3 is selected, the login screen is displayed, gnome-shell is loaded as expected, and unity-settings-daemon does not crash.

[Launchpad Janitor (janitor)]

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

[dino99 (9d9)]

lightdm fatal error

[Shannon VanWagner (shannon-vanwagner)]

This seems to have fixed the problem for me:

sudo systemctl disable lightdm
sudo systemctl stop lightdm
sudo systemctl enable gdm #Seems to fail
sudo systemctl start gdm
sudo dpkg-reconfigure gdm3 #Shows lightdm selected
select gdm3, push enter

Reboot

[Jeremy Bícha (jbicha)]

I suspect this is a duplicate of LP: #1722920 since unity-greeter uses unity-settings-daemon.

https://launchpad.net/ubuntu/+source/gnome-settings-daemon/3.26.1-0ubuntu4

[Till Kamppeter (till-kamppeter)]

I encountered the same problem today and after some trying around I came to the idea of changing the greeter, entered the first four commands of comment #9 (without having seen this bug report yet) and this way got back in again. Then I googled for the problem and found this bug report.

I am using a 2nd generation Lenovo X1 Carbon and during Artful development Wayland did not work for me and so I always worked in the "GNOME with Xorg" session. The greeter was LightDM (looked the same as the one of Zesty).

[Till Kamppeter (till-kamppeter)]

Jeremy, why do we still have unity-settings-daemon after discontinuing Unity? Why not also discontinue LightDM or make it use gnome-settings-daemon?

[dino99 (9d9)]

Lightdm works again since that upgrade:

This bug was fixed in the package gnome-settings-daemon - 3.26.1-0ubuntu4

---------------
gnome-settings-daemon (3.26.1-0ubuntu4) artful; urgency=medium

  * debian/patches/ubuntu-lid-close-suspend.patch:
    - restore the patch for the schemas part (and delete the code),
      those keys are used by unity-settings-daemon (lp: #1722920)

 -- Sebastien Bacher <email address hidden> Thu, 12 Oct 2017 16:45:31 +0200

[Till Kamppeter (till-kamppeter)]

I can also confirm that LightDM is working again.

[dino99 (9d9)]

@Till

i have not closed the report as your #12 comment makes sense; so waiting for Jeremy (or else dev) opinion.

[Jeremy Bícha (jbicha)]

I'm marking as duplicate since this bug is no longer reproducible after today's updates according to the comments here.

Till, Ubuntu 17.10 does use GDM by default. And if you upgrade now from 17.04, you should be transitioned from LightDM to GDM automatically (unless you have other desktop environments installed I think).

LightDM itself does not use either unity-settings-daemon or gnome-settings-daemon. unity-greeter though does use unity-settings-daemon. Unity requires unity-settings-daemon to be installed for the lockscreen.

While I'd love to see unity-settings-daemon be removed, it would cause regressions with keyboard shortcuts ("hotkeys") and gnome-control-center's Displays panel wouldn't work. These are fixable with developer effort (GNOME Flashback managed to fix both of these issues) but there aren't really developers working on improving Unity now.