(<unknown>:2018): Gdk-WARNING **: cannot open display:
i.e. if the display can't be opened for some reason, trying to load
(gnome gtk) causes the program simply to exit... which I suppose is
correct behavior, but might it be nice to have a way of catching the
error so that a program could, for example, print out a "hey, I can't
open any displays, what should I do" type of message?