Building basic gtkd,opengl application

[Michał via Digitalmars-d-learn]

I am trying to make some application using gtkd and opengl.
I have made simple program but it didn't work and I have no idea 
why.

I have never used gtk so maybe I'm doing something stupid : /

The code:
http://pastebin.com/7NfbMqaK

Error:
http://pastebin.com/vaFAP0bu

Some ideas?
Any tips to gtkd/gtk/gl are welcome.