snap 2.31.2 broke almost all my snaps

[James Troup]

After an upgrade to snap 2.31.2, I can no longer use almost all my snaps, e.g.:

james@malefic:~$ kubectl
internal error, please report: running "kubectl" failed: cannot find installed snap "kubectl" at revision 367
james@malefic:~$

and indeed, snap list shows most of them as broken:

james@malefic:~$ snap list | grep -cw broken
17
james@malefic:~$

6 are not:

james@malefic:~$ snap list | grep -vw broken
Name Version Rev Developer Notes
brave v0.21.24dev 18 brave -
core 16-2.31.2 4206 canonical core
keepassxc 2.3.1 37 keepassxreboot -
spotify 1.0.77.315.g4d3f03c7-5 11 spotify -
telegram-desktop 1.2.14 113 3v1n0 -
james@malefic:~$

And indeed the only mounts I can see are for those snaps, all the other snaps don't have any mounts.

This is on Ubuntu 16.04. Please let me know if I can provide more detail.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: snapd 2.31.2
ProcVersionSignature: Ubuntu 4.13.0-36.40~16.04.1-generic 4.13.13
Uname: Linux 4.13.0-36-generic x86_64
NonfreeKernelModules: zfs zunicode zavl zcommon znvpair
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Mar 23 00:46:19 2018
InstallationDate: Installed on 2016-08-05 (594 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
SourcePackage: snapd
UpgradeStatus: No upgrade log present (probably fresh install)

[Gustavo Niemeyer (niemeyer)]

Sorry for the trouble, James. A reboot is the most trivial workaround, and the fix is being released.

We got bitten by a misbehavior in systemd, which got hidden due to lack of testing for double updates (update, and update again on itself).

Here are the details:

https://bugs.launchpad.net/ubuntu/+source/snapd/+bug/1756793