Container fails to start: "Error reading host's cpuset.cpus"

When launching a container the container builds but then fails to start. Syslog has an error about being unable to read cpusets:

Apr  8 15:31:50 pirx lxd.daemon[4001]: time="2022-04-08T15:31:50+02:00" level=error msg="Error reading host's cpuset.cpus"

I’ve tried to launch both a focal and an impish container with similar results.

Host is impish, running latest/stable: 5.0.0-c5bcb80

It seems this could be a cgroups incompatib. however I’m not sure why it would fail even when container and host are on the same release (impish)

Any pointers?

How does it fail to start exactly?

Pretty much silently. The lxc launch returns, I only see it being “Stopped” when doing lxc list

Same with lxc start.

The only indication of a fault is in the syslog

Some more context from syslog

Apr  8 13:57:47 pirx kernel: [18410.174073] lxdbr0: port 2(vethd753a130) entered blocking state
Apr  8 13:57:47 pirx kernel: [18410.174076] lxdbr0: port 2(vethd753a130) entered forwarding state
Apr  8 13:57:47 pirx systemd[3816]: snap.lxd.lxc.6b75d365-4f9b-4017-a0d6-a8d2977bfed2.scope: Deactivated successfully.
Apr  8 13:57:47 pirx systemd[3816]: Started snap.lxd.lxc.1c7a177e-88bc-48fa-a4fd-a8650fa79676.scope.
Apr  8 13:57:47 pirx kernel: [18410.305205] lxdbr0: port 2(vethd753a130) entered disabled state
Apr  8 13:57:47 pirx kernel: [18410.345068] lxdbr0: port 2(vethd753a130) entered blocking state
Apr  8 13:57:47 pirx kernel: [18410.345073] lxdbr0: port 2(vethd753a130) entered forwarding state
Apr  8 13:57:47 pirx kernel: [18410.365369] lxdbr0: port 2(vethd753a130) entered disabled state
Apr  8 13:57:47 pirx systemd-resolved[2269]: veth65f63a64: Bus client set search domain list to: lxd
Apr  8 13:57:47 pirx dnsmasq[4443]: using local addresses only for domain lxd
Apr  8 13:57:47 pirx dnsmasq[4443]: using local addresses only for domain lxd
Apr  8 13:57:47 pirx NetworkManager[2366]: <info>  [1649419067.7713] device (vethd753a130): released from master device lxdbr0
Apr  8 13:57:47 pirx systemd[3816]: snap.lxd.lxc.1c7a177e-88bc-48fa-a4fd-a8650fa79676.scope: Deactivated successfully.
Apr  8 13:57:48 pirx lxd.daemon[4001]: time="2022-04-08T13:57:48+02:00" level=error msg="Error reading host's cpuset.cpus"
Apr  8 13:57:48 pirx kernel: [18411.207777] audit: type=1400 audit(1649419068.567:214): apparmor="STATUS" operation="profile_remove" profile="unconfined" name="lxd-charmcraft_charmcraft-cloudsupport-35528151-0-0-amd64_</var/snap/lxd/common/lxd>" pid=113580 comm="apparmor_parser"