The old Duit files should be removed from svn, so that people won't get mixed up by them. No-one is ever going to know to look inside a folder named /trunk/gtkD/src/ when there's /trunk/src/ available.
This problem comes from the way the name change from Duit to gtkD was done. It was done by copying everything to a folder called /trunk/gtkD/, so the old Duit files were left there in /trunk/. So, next time somebody does some updates on the svn: Please do svn delete on the all the Duit files. They aren't needed anymore, and they can always be accessed later as this is a version control system.