I have been updating a legacy system from 3.0.3 LXD from 18.04 repo to 5.0 snap.
lxd.migrate
detected 3.0.3 to 5.0 and offered to continue upgrading.
This broke.
ERROR [2022-07-11T18:44:30+02:00] Failed to start the daemon err="Unsupported upgrade path, please first upgrade to LXD 4.0"
I believe LXD should detect 3.x to 5.x upgrade and fail with an error, or at least throw a warning