dmd / rdmd is calling the Microsoft linker instead of the one from Digital Mars. Try...

Try this http://gtkd.org/Downloads/GtkDGL.zip

...gl stuff is included in the final GtkD.lib when budding?  It's weird though...

...LINK : fatal error LNK1104: cannot open file 'gtkd.lib'
Microsoft (R) Library Manager Version 11...

Don't know if this helps but I did a dumpbin on the original COFF...

...code is:

/*
 * This file is part of gtkD.
 *
 * dui is free software; you can redistribute...

Okay, works now!

The last problem I had was with the path.  Solution:  place your...

Try putting the path to the Gtk3 runtime at the start of the path, and...

Should I try removing everything gtk-using and related from my
system?

I get the same errors except for the zlib ones when all Gtk-runtimes are...