Acabei de instalar o Ubuntu 15.04 e o ambiente de desktop Gnome 3. Se eu tentar executar um programa GUI a partir da linha de comando (como o Gedit), obtenho:
XXXXX:~$ gedit
No protocol specified
** (gedit:3299): WARNING **: Could not open X display
No protocol specified
gdk_mir_display_open
Failed to connect to Mir: Failed to connect to server socket: No such file or directory
Unable to init server: Could not connect: Connection refused
(gedit:3299): Gtk-WARNING **: cannot open display: :0
But, if I launch gedit from the gnome "search" window, it comes up fine.
I have some custom GUIs I use and I typically start them from the command line.
p.s. Eu não posso usar o ambiente de trabalho do Ubuntu. b / c de problemas com a Nvidia HW.