Luckily I had a snapshot from earlier. Bisecting upgrades shows that the problem is in one of these packages:
libpam-systemd/yakkety 231-4 amd64 [upgradable from: 231-1] libsystemd-dev/yakkety 231-4 amd64 [upgradable from: 231-1] libsystemd0/yakkety 231-4 amd64 [upgradable from: 231-1] systemd/yakkety 231-4 amd64 [upgradable from: 231-1] systemd-sysv/yakkety 231-4 amd64 [upgradable from: 231-1] With these packages installed, I have: * Screen lock/dpms is broken * A lot of startup programs don't run (weather indicator, nm-applet, tomboy notes, system load indicator, for instance) * I get a black screen background at startup (until I run nautilus manually). ** Package changed: gnome-screensaver (Ubuntu) => systemd (Ubuntu) ** Summary changed: - screen lock and dpms broken in yakkety + systemd update breaks screen lock, dpms, startup programs -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1615184 Title: systemd update breaks screen lock, dpms, startup programs Status in systemd package in Ubuntu: New Bug description: This morning's updates broke both the screen lock (it never auto-locks now) and dpms (if you manually lock the screen, it doesn't turn off any more). "xset dpms force off" still works to turn the screen off and "gnome- screensaver-command -l" still locks the screen, so it probably isn't gnome-screensaver's fault. Is it a lightdm issue perhaps? Which app is in charge of this? ProblemType: Bug DistroRelease: Ubuntu 16.10 Package: gnome-screensaver 3.6.1-7ubuntu4 ProcVersionSignature: Ubuntu 4.4.0-9134.53-generic 4.4.15 Uname: Linux 4.4.0-9134-generic x86_64 ApportVersion: 2.20.3-0ubuntu7 Architecture: amd64 CurrentDesktop: Unity Date: Sat Aug 20 12:22:54 2016 GnomeSessionIdleInhibited: Unknown GnomeSessionInhibitors: Failed to acquire GsettingsGnomeSession: org.gnome.desktop.session session-name 'ubuntu' org.gnome.desktop.session idle-delay uint32 60 InstallationDate: Installed on 2016-07-04 (46 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1) JournalErrors: Error: command ['journalctl', '-b', '--priority=warning', '--lines=1000'] failed with exit code 1: Hint: You are currently not seeing messages from other users and the system. Users in the 'systemd-journal' group can see all messages. Pass -q to turn off this notice. No journal files were opened due to insufficient permissions. SourcePackage: gnome-screensaver UpgradeStatus: Upgraded to yakkety on 2016-07-24 (26 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1615184/+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