Hmm, the instructions above should have worked. They rely on you having udev inside of the instance and having udev generate the /dev/virtio-ports/ devices on boot. When those show up, the systemd unit will get called.
So it’d be interesting to look closer at what’s going on on boot following running install.sh to see if there’s an issue on our end or something weird going on with the particular VM.
For 14.04 and FreeBSD, that gets trickier. If they’re using systemd and have kernel drivers for virtio-serial, 9p and virtio-vsock, then install.sh is the way to go. But that’s not going to cut it for FreeBSD.
There, your best bet is to setup a local user that you can use with incus console and get SSH up for normal day to day access.
The work done in Incus 0.5 makes it possible to get a FreeBSD agent eventually, but someone will need to do some work to make such an agent build possible.