Troubles with new sdk with docker on linux

new laptop == new environment.
i have elementaryos based on ubuntu bionic, i have installed sailfish sdk with docker option, now build engine wont start

i have following errors:
pkg-config is not available. Ensure it is installed and available from PATH
Error connecting to “sailfish-os-build-engine” virtual machine: Failed to start virtual machine “sailfish-os-build-engine”

i also have no docker images in my local docker. docker images returns nothing.
when should that have been downloaded ?

ok answering my own question:

  • the obvious pkg-config needs to be installed.

what i did miss was to enable docker deamon to run without sudo