ubuntu-core/core unconditionally switches to the stable channel on all-snap images

[Alan Pope 🍺🐧🐱 🦄]

My Pi2 seems to be broken in such a way that I can't run any apps, nor query snaps:-

popey@localhost:~$ snap list
error: cannot list snaps: cannot communicate with server: Get http://localhost/v2/snaps: dial unix /run/snapd.socket: connect: connection refused

popey@localhost:~$ ls /snap
bin classic htop pi2 pi2-kernel snap-codelabs snapweb ubuntu-core

popey@localhost:~$ htop
internal error, please report: running "htop" failed: cannot list snaps: cannot communicate with server: Get http://localhost/v2/snaps: dial unix /run/snapd.socket: connect: connection refused

[Alan Pope 🍺🐧🐱 🦄 (popey)]

Seems I'm not on 845

popey@localhost:~$ fw_printenv | grep ^snap_core
snap_core=ubuntu-core_424.snap

[Oliver Grawert (ogra)]

424 is the last stable release, if you were on 845 before this means your system switched unconditionally to the stable channel.

[Alan Pope 🍺🐧🐱 🦄 (popey)]

Yes, it appears my Pi has switched to the stable channel without me asking.

As ogra suggested on irc, I have issued:-

sudo fw_setenv snap_core ubuntu-core_845.snap
sudo reboot

Now I can't even run snap list, it hangs.

Also I note some odd things in dmesg (attached):-

[ 14.799466] F2FS-fs (ram8): Magic Mismatch, valid(0xf2f52010) - read(0x0)
[ 14.799476] F2FS-fs (ram8): Can't find valid F2FS filesystem in 1th superblock

[Oliver Grawert (ogra)]

this is "normal" in new versions, while looking for it's assertions snapd seems to attempt to loop over some mountpoints trying various filesystems. which results in this log spam.

[Pat McGowan (pat-mcgowan)]

dupe of lp:1628914 ?