I was using in past to upgrade my HASS installed in a virtualenv on PI the procedure described here: https://home-assistant.io/docs/installation/virtualenv/ but it has been simplified a lot and now not working on my system !! It looks like it’s missing the command to switch to HA user ! Is there somewhere accessible the old complete procedure ??
But the simplification seems to have gone too far. There doesn’t seem to be equivalent procedures described elsewhere. Maybe someone is trying to force you to use hassio.