Turns out this was already fixed upstream a few days ago: https://github.com/systemd/systemd/pull/2834 . I cherry-picked the fix.
** Changed in: systemd (Ubuntu) Status: New => Fix Committed ** Changed in: systemd (Ubuntu) Assignee: (unassigned) => Martin Pitt (pitti) -- 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/1560695 Title: Assertion 'b' failed at ../src/basic/path-util.c:390, function path_compare() Status in systemd package in Ubuntu: Fix Committed Bug description: Before the error occurs, the only thing that was plugged into the computer moments before was a flash drive in the USB port (3.0). After that a few moments after the error occurred. ProblemType: Crash DistroRelease: Ubuntu 16.04 Package: systemd 229-2ubuntu1 ProcVersionSignature: Ubuntu 4.4.0-15.31-generic 4.4.6 Uname: Linux 4.4.0-15-generic x86_64 NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia ApportVersion: 2.20-0ubuntu3 Architecture: amd64 Date: Tue Mar 22 18:34:35 2016 ExecutablePath: /lib/systemd/systemd InstallationDate: Installed on 2016-03-19 (3 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160307) MachineType: Dell Inc. Vostro 5470 ProcCmdline: /sbin/init splash ProcEnviron: TERM=linux PATH=(custom, no user) ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-15-generic.efi.signed root=UUID=c1651082-fabc-4b0c-b328-6c708e33f208 ro quiet splash vt.handoff=7 Signal: 6 SourcePackage: systemd StacktraceTop: __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54 __GI_abort () at abort.c:89 ?? () ?? () ?? () SystemdDelta: [EXTENDED] /lib/systemd/system/rc-local.service → /lib/systemd/system/rc-local.service.d/debian.conf [EXTENDED] /lib/systemd/system/systemd-timesyncd.service → /lib/systemd/system/systemd-timesyncd.service.d/disable-with-time-daemon.conf [EXTENDED] /etc/systemd/system/display-manager.service → /lib/systemd/system/display-manager.service.d/xdiagnose.conf 3 overridden configuration files found. SystemdFailedUnits: Error: command ['systemctl', 'status', '--full', 'Error:'] failed with exit code 1: Failed to get properties: Failed to activate service 'org.freedesktop.systemd1': timed out Title: systemd crashed with SIGABRT in __GI_raise() UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: dmi.bios.date: 01/21/2015 dmi.bios.vendor: Dell Inc. dmi.bios.version: A11 dmi.board.name: 0F7NWH dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: 0.1 dmi.modalias: dmi:bvnDellInc.:bvrA11:bd01/21/2015:svnDellInc.:pnVostro5470:pvr:rvnDellInc.:rn0F7NWH:rvrA00:cvnDellInc.:ct8:cvr0.1: dmi.product.name: Vostro 5470 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1560695/+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