This was a system that generally stayed on 24/7, so I am not sure what updates might have caused this to happen. The last update before the system rebooted occurred at "Start-Date: 2018-03-31 09:57:33", see attached update history file.
I should also add that I have been using lightdm along with LXDE on this system. When the error originally occurred, another failure message was "lightdm: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory" so I then proceeded to install libpam-kwallet4 and libpam-kwallet5 (as you can see in the install history), which made that error go away, but the lightdm startup problem persisted. I then attempted to install and use gdm, but it failed as well. I then tried lxdm and it succeeded, except that there were many applications that could not be launched once logged into the environment. I believe the problem has something to do with lightdm and gdm not being able to unlock a keyring of some sort, but I don't see libpam-kwallet4 or libpam-kwallet5 mentioned as dependency for it. ** Attachment added: "history.log" https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1760371/+attachment/5097642/+files/history.log -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/1760371 Title: Light Display Manager fails to start Status in lightdm package in Ubuntu: New Bug description: 1) Output of lsb_release -rd: Description: Ubuntu 16.04.4 LTS Release: 16.04 2) Output of apt-cache policy lightdm: lightdm: Installed: 1.18.3-0ubuntu1.1 Candidate: 1.18.3-0ubuntu1.1 Version table: *** 1.18.3-0ubuntu1.1 500 500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages 100 /var/lib/dpkg/status 1.18.1-0ubuntu1 500 500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages 3) What I expected to happen: - Expected the display manager to take me to the lightdm user login screen. 4) What happened instead: - lightdm made 5 attempts to start before failing. Failure messages were "failed to start Detect the available GPUs and deal with any system changes" and "Failed to start Light Display Manager". ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: lightdm 1.18.3-0ubuntu1.1 ProcVersionSignature: Ubuntu 4.4.0-116.140-generic 4.4.98 Uname: Linux 4.4.0-116-generic x86_64 NonfreeKernelModules: zfs zunicode zcommon znvpair zavl wl ApportVersion: 2.20.1-0ubuntu2.15 Architecture: amd64 Date: Sat Mar 31 17:43:08 2018 InstallationDate: Installed on 2015-11-23 (859 days ago) InstallationMedia: ProcEnviron: TERM=linux PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/zsh SourcePackage: lightdm UpgradeStatus: Upgraded to xenial on 2017-01-18 (437 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1760371/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
