Please test your changes...
$ sudo adduser --quiet --system nut --home /var/lib/nut --no-create-home nut adduser: Specify only one name in this mode.
I guess you want
adduser --quiet --system --group --home /var/lib/nut --no-create-home nut
Please test your changes...
$ sudo adduser --quiet --system nut --home /var/lib/nut --no-create-home nut
adduser: Specify only one name in this mode.
I guess you want
adduser --quiet --system --group --home /var/lib/nut --no-create-home nut