How to compile with GtkD [solved]

[mark]

Turns out I didn't need to add lines to dub.sdl at all. So my 
dub.sdl is now just:

name "gtktest"
description "Gtk Test"
authors "Mark"
targetType "executable"
dependency "gtk-d:gtkd" version=">=3.9.0"

The solution was to do this:

$ dub add-path ~/opt/GtkD3/

After that it does static builds, which is great, gives me 
self-contained executables.