For me, this problem occurs in Ubuntu-18.04 and 20.04. It occurs when dynamic hostnames are used. However, different errors seem to cause the LightDM sessions to fail. But you can look at the logs to see how many "new session c" sessions are logged. After a reboot and one login, there should only be two (using a single display). The problem occurs because lightdm starts before the hostname is changed from localhost to the one from DNS. So all we have to do is start lightdm after that by simply changing /lib/systemd/system/lightdm.service to add "network- online.target" to the end of this line:
After=systemd-user-sessions.service [email protected] plymouth- quit.service It works if the network is not plugged in too--the hostname remains localhost. This is my solution. Maybe an expert can review it to see if it is the right change and hopefully backport it to Ubuntu-18.04 too. -- You received this bug notification because you are a member of LightDM Gtk+ Greeter Development Team, which is subscribed to lightdm-gtk- greeter in Ubuntu. https://bugs.launchpad.net/bugs/1422794 Title: lightdm-gtk-greeter crashed with SIGSEGV in cairo_surface_get_type() Status in lightdm-gtk-greeter package in Ubuntu: Incomplete Bug description: I'm on Xubuntu 15.04 Daily Build. I simply changed the desktop environment in the Login screen from Xubuntu to Xfce, logged in, and was told that a system problem was detected before the panels/icons of the desktop environment even loaded. ProblemType: Crash DistroRelease: Ubuntu 15.04 Package: lightdm-gtk-greeter 2.0.0-0ubuntu1 ProcVersionSignature: Ubuntu 3.18.0-13.14-generic 3.18.5 Uname: Linux 3.18.0-13-generic x86_64 ApportVersion: 2.16.1-0ubuntu2 Architecture: amd64 Date: Tue Feb 17 11:01:23 2015 ExecutablePath: /usr/sbin/lightdm-gtk-greeter InstallationDate: Installed on 2015-02-10 (7 days ago) InstallationMedia: Xubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150208) ProcCmdline: /usr/sbin/lightdm-gtk-greeter ProcEnviron: PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/false SegvAnalysis: Segfault happened at: 0x7f010b7f7870 <cairo_surface_get_type>: mov 0x10(%rdi),%eax PC (0x7f010b7f7870) ok source "0x10(%rdi)" (0x00000010) not located in a known VMA region (needed readable region)! destination "%eax" ok SegvReason: reading NULL VMA Signal: 11 SourcePackage: lightdm-gtk-greeter StacktraceTop: cairo_surface_get_type () from /usr/lib/x86_64-linux-gnu/libcairo.so.2 greeter_background_save_xroot () _start () Title: lightdm-gtk-greeter crashed with SIGSEGV in cairo_surface_get_type() UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm-gtk-greeter/+bug/1422794/+subscriptions -- Mailing list: https://launchpad.net/~lightdm-gtk-greeter-team Post to : [email protected] Unsubscribe : https://launchpad.net/~lightdm-gtk-greeter-team More help : https://help.launchpad.net/ListHelp
