snap just updated lxd to 4.21 and lxc start responds with:
Error: Failed to start device “X0”: Failed opening source path “/var/lib/snapd/hostfs/tmp/.X11-unix/X0”: open /var/lib/snapd/hostfs/tmp/.X11-unix/X0: no such device or address
The device X0 is defined in the container’s profile like so:
X0:
path: /tmp/.X11-unix/X0
source: /tmp/.X11-unix/X0
type: disk
Other containers without this mapping start w/out issues.