If you installed python 3.6 from ppa:jonathonf/python-3.6 on ubuntu 16.04, don’t run apt-get update && apt-get upgrade.
Python get’s updated to 3.6.5 and after HA restart some components (broadlink for me) didn’t work anymore.
Also pip doesn’t run, and creating a new venv ended in errors.
Had to recover from a backup. (Good to have one 
)
Lucky, I got screwed lol. Spent yesterday doing a fresh install if 18.04 and moved all of my apps to docker which I had been planning on doing.
So HA has an general incompatibility with python 3.6.5? Or is this problem specific to the combination Ubuntu 16.04 and Python from PPA?
Not doing apt update/upgrade isn’t an option in the long run.
I don’t know.
I deactivated the ppa, so 16.04 can be updated.