Sudo apt update starting/using default sys-net

[whoami]

Interesting!

… but as you wrote

@unman

Break down your target in to small steps.
Keep the specification of the target and of each step as minimal as
possible.
Focus on solving each small step in order.
Once you have solved one, move on to the next.

I have to finish my minimal debian template script first. I have already spent so many weekends on it (1000+ lines). I also learnt so much Qubes / Linux / Bash coding, … apt keys … but it is a very tough route to go.