GtkFB cannot open display, although framebuffer device is working

[Mario Moder <oddfellow arcor de>]

Hi!

I compiled GTK+-2.2.0 with

--with-gdktarget=linux-fb
--without-x

but when I start gtk-demo it says

Gtk-WARNING **: cannot open display:

I run it as root, the framebuffer device is set up
correctly, /dev/console and /dev/fb0 is a+rw, and /dev/mouse
is a link to /dev/ttyS1, where my serial mouse is connected.

Other framebuffer apps like fbi (non-GTK+) work, so the
fault is not the framebuffer device and its settings.

What's wrong?

Mario