So did you login as user joachim and running something like 'sudo ./setup'
Or did you drop to a root shell first (I.e. su) and then try to run ./setup
Or did you log into, and therefore start X, as root and then run ./setup?
Can you run a standard x program from the command line, like xclock, or do you get the same error?
To get display working, execute these commands (xhost + doesn't work):xhost local:rootxhost local:<your userid>