Instead of
./setup.sh try
sh setup.sh. If Debian doesn't allow you to run GUI programs as root, you also need to run the following command:
Code:
ln -fs /home/user_name/.Xauthority /root/.Xauthority
(Where you, of course, replace the "user_name" part with
your user name.)
Removing the .Xauthority link from the /root directory will revert Debian back to its original permissions that only allow the user who initially started X to run GUI applications. In general, it's safer to install a helper program like gksu or kdesu and use that to temporarily run GUI apps with root privileges.