[Pkg-xfce-devel] Bug#837895: lightdm-gtk-greeter: GUI does not run, black screen, on startup

Sun Sep 25 16:20:31 UTC 2016

I am having the same problem.  My dmesg does not show the trap reported
by the OP.  But the symptoms are exactly the same.  I have subscribed to
this bug report.  I am using systemd and xfce.  Here are some files whose
content may be relevant:

/usr/share/lightdm/lightdm.conf.d/01_debian.conf:

-----

# Debian specific defaults
#
# - use lightdm-greeter session greeter, points to the etc-alternatives managed
# greeter
# - hide users list by default, we don't want to expose them
# - use Debian specific session wrapper, to gain support for
# /etc/X11/Xsession.d scripts

[Seat:*]
greeter-session=lightdm-greeter
greeter-hide-users=true
session-wrapper=/etc/X11/Xsession

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/etc/alternatives/lightdm-greeter (a symbolic link to
/usr/share/xgreeters/lightdm-gtk-greeter.desktop):

-----

[Desktop Entry]
Name=LightDM GTK+ Greeter
Comment=This runs the GTK+ greeter, it should only be run from LightDM
Exec=lightdm-gtk-greeter
Type=Application
X-Ubuntu-Gettext-Domain=lightdm

-----

Note that I am running pure Debian, not Ubuntu.  I wonder if
X-Ubuntu-Gettext-Domain should be in the above file?

/etc/lightdm/users.conf:

-----

#
# User accounts configuration
#
# NOTE: If you have AccountsService installed on your system, then LightDM will
# use this instead and these settings will be ignored
#
# minimum-uid = Minimum UID required to be shown in greeter
# hidden-users = Users that are not shown to the user
# hidden-shells = Shells that indicate a user cannot login
#
[UserList]
minimum-uid=500
hidden-users=nobody nobody4 noaccess
hidden-shells=/bin/false /usr/sbin/nologin

-----

Note that the lightdm user on my system has a uid of 113.

/var/log/lightdm/lightdm.log:

-----

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.18.2, UID=0 PID=3285
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/01_debian.conf
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: Registered seat module xlocal
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Registered seat module unity
[+0.02s] DEBUG: Monitoring logind for seats
[+0.02s] DEBUG: New seat added from logind: seat0
[+0.02s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.02s] DEBUG: Seat seat0: Starting
[+0.02s] DEBUG: Seat seat0: Creating greeter session
[+0.02s] DEBUG: Seat seat0: Creating display server of type x
[+0.02s] DEBUG: Could not run plymouth --ping: Failed to execute child process "plymouth" (No such file or directory)
[+0.02s] DEBUG: Using VT 7
[+0.02s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.02s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.02s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.02s] DEBUG: DisplayServer x-0: Launching X Server
[+0.02s] DEBUG: Launching process 3292: /usr/bin/X :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.02s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.02s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.02s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.04s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.04s] DEBUG: User /org/freedesktop/Accounts/User1001 added
[+0.04s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+0.10s] DEBUG: Seat seat0 changes active session to
[+0.10s] CRITICAL: session_get_login1_session_id: assertion 'session != NULL' failed
[+0.64s] DEBUG: Got signal 10 from process 3292
[+0.64s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+0.64s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+0.64s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+0.65s] DEBUG: Session pid=3311: Started with service 'lightdm-greeter', username 'lightdm'
[+0.68s] DEBUG: Session pid=3311: Authentication complete with return value 0: Success
[+0.68s] DEBUG: Seat seat0: Session authenticated, running command
[+0.68s] DEBUG: Session pid=3311: Running command /usr/sbin/lightdm-gtk-greeter
[+0.68s] DEBUG: Creating shared data directory /var/lib/lightdm/data/lightdm
[+0.68s] DEBUG: Session pid=3311: Logging to /var/log/lightdm/seat0-greeter.log
[+0.82s] DEBUG: Activating VT 7
[+0.82s] DEBUG: Activating login1 session c2
[+1.34s] DEBUG: Greeter connected version=1.18.2 resettable=false
[+2.58s] DEBUG: Greeter start authentication
[+2.58s] DEBUG: Session pid=3336: Started with service 'lightdm', username '(null)'
[+2.60s] DEBUG: Session pid=3336: Got 1 message(s) from PAM
[+2.60s] DEBUG: Prompt greeter with 1 message(s)
[+11.76s] DEBUG: Seat seat0 changes active session to 4
[+21.93s] DEBUG: Got signal 15 from process 1
[+21.93s] DEBUG: Caught Terminated signal, shutting down
[+21.93s] DEBUG: Stopping display manager
[+21.93s] DEBUG: Seat seat0: Stopping
[+21.93s] DEBUG: Seat seat0: Stopping display server
[+21.93s] DEBUG: Sending signal 15 to process 3292
[+21.93s] DEBUG: Seat seat0: Stopping session
[+21.93s] DEBUG: Session pid=3311: Sending SIGTERM
[+21.93s] DEBUG: Seat seat0: Stopping session
[+21.93s] DEBUG: Session pid=3336: Sending SIGTERM
[+21.94s] DEBUG: Session pid=3336: Terminated with signal 15
[+21.94s] DEBUG: Session: Failed during authentication
[+21.94s] DEBUG: Seat seat0: Session stopped
[+21.96s] DEBUG: Process 3292 exited with return value 0
[+21.96s] DEBUG: DisplayServer x-0: X server stopped
[+21.96s] DEBUG: Releasing VT 7
[+21.96s] DEBUG: DisplayServer x-0: Removing X server authority /var/run/lightdm/root/:0
[+21.96s] DEBUG: Seat seat0: Display server stopped
[+22.01s] DEBUG: Greeter closed communication channel
[+22.01s] DEBUG: Session pid=3311: Exited with return value 0
[+22.01s] DEBUG: Seat seat0: Session stopped
[+22.01s] DEBUG: Seat seat0: Stopped
[+22.01s] DEBUG: Display manager stopped
[+22.01s] DEBUG: Stopping daemon
[+22.03s] DEBUG: Exiting with return value 0

-----

/var/log/lightdm/seat0-greeter.log:

-----

** Message: Starting lightdm-gtk-greeter 2.0.1 (Jun 21 2015, 09:50:04)
** Message: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/01_debian.conf
** Message: [Configuration] Reading file: /etc/lightdm/lightdm-gtk-greeter.conf

** (lightdm-gtk-greeter:3317): WARNING **: [PIDs] Failed to execute command: upstart

** (process:3322): WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files

(lightdm-gtk-greeter:3317): GdkPixbuf-CRITICAL **: gdk_pixbuf_new: assertion 'width > 0' failed

(lightdm-gtk-greeter:3317): GdkPixbuf-CRITICAL **: gdk_pixbuf_composite: assertion 'GDK_IS_PIXBUF (dest)' failed

(lightdm-gtk-greeter:3317): GLib-GObject-CRITICAL **: g_object_ref: assertion 'G_IS_OBJECT (object)' failed

** (lightdm-gtk-greeter:3317): WARNING **: [Background] Failed to read wallpaper: /usr/share/images/desktop-base/login-background.svg

(lightdm-gtk-greeter:3317): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed

(lightdm-gtk-greeter:3317): GdkPixbuf-CRITICAL **: gdk_pixbuf_new: assertion 'width > 0' failed

(lightdm-gtk-greeter:3317): GdkPixbuf-CRITICAL **: gdk_pixbuf_composite: assertion 'GDK_IS_PIXBUF (dest)' failed

(lightdm-gtk-greeter:3317): GLib-GObject-CRITICAL **: g_object_ref: assertion 'G_IS_OBJECT (object)' failed

** (lightdm-gtk-greeter:3317): WARNING **: [Background] Failed to read wallpaper: /usr/share/images/desktop-base/login-background.svg

(lightdm-gtk-greeter:3317): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed

(lightdm-gtk-greeter:3317): GdkPixbuf-CRITICAL **: gdk_pixbuf_new: assertion 'width > 0' failed

(lightdm-gtk-greeter:3317): GdkPixbuf-CRITICAL **: gdk_pixbuf_composite: assertion 'GDK_IS_PIXBUF (dest)' failed

(lightdm-gtk-greeter:3317): GLib-GObject-CRITICAL **: g_object_ref: assertion 'G_IS_OBJECT (object)' failed

** (lightdm-gtk-greeter:3317): WARNING **: [Background] Failed to read wallpaper: /usr/share/images/desktop-base/login-background.svg

(lightdm-gtk-greeter:3317): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed

(lightdm-gtk-greeter:3317): Gtk-WARNING **: Drawing a gadget with negative dimensions. Did you forget to allocate a size? (node menubar owner GreeterMenuBar)

(lightdm-gtk-greeter:3317): Gdk-WARNING **: lightdm-gtk-greeter: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.

-----

/var/log/lightdm/x-0-greeter.log:

-----

** Message: Starting lightdm-gtk-greeter 2.0.1 (Jun 21 2015, 09:50:04)
** Message: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/01_debian.conf
** Message: [Configuration] Reading file: /etc/lightdm/lightdm-gtk-greeter.conf

** (lightdm-gtk-greeter:18795): WARNING **: [PIDs] Failed to execute command: upstart

** (process:18800): WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files

(lightdm-gtk-greeter:18795): Gtk-WARNING **: Drawing a gadget with negative dimensions. Did you forget to allocate a size? (node menubar owner GreeterMenuBar)

(lightdm-gtk-greeter:18795): Gdk-WARNING **: lightdm-gtk-greeter: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.

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x-0.log shows no errors.  Is there any other file you wish to see?

-- 
  .''`.     Stephen Powell    <zlinuxman at fastmail.com>
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