Using latest Debian sid, there might be a problem with gparted being run within KDE, failing to load the $DISPLAY.

$ sudo gparted
No protocol specified

(gpartedbin:3160): Gtk-WARNING **: cannot open display: :0

normally you would then keep the display within sudo session (# visudo and add Defaults env_keep=DISPLAY), but install kdesudo will resolve the actual problem (don’t keep the display with sudo, otherwise kdesudo will fail!).

$ sudo apt-get update ; apt-get install kdesudo
$ kdesudo gparted
%d bloggers like this: