"make index" fails

[Robert Huff]

	For the last 2-3 days, "cd /usr/ports && make index" has failed
with: 

>  --- describe.x11-themes ---
>  --- describe.x11-toolkits ---
>  --- describe.x11-wm ---
>  make_index: /usr/ports/x11/nvidia-driver: no entry for /usr/ports/graphics/linux-c6-libglvnd
>   Done.

	Is this a fault on my end, or is there a hiccup in the ports
tree?
	And if the former, how do I fix it?


			Respectfully,


				Robert Huff