Just installed Mesa meta-package from a recent /usr/pkgsrc,
when trying to build the code I get:

0rasputin@idoru:bhole$ make
gcc -Wall -I/usr/X11R6/include/  -c bhole.c
gcc -Wall -I/usr/X11R6/include/ -o bhole -L/usr/X11R6/lib  -lX11 -lXi -lXmu -lglut -lGL -lGLU -lm
/usr/lib/crt0.o: In function `___start':
/usr/lib/crt0.o(.text+0xc1): undefined reference to `main'
collect2: ld returned 1 exit status
*** Error code 1


Source is at:
http://linux.oreillynet.com/lpt/a//linux/2000/09/15/blackhole.html
(nice little hack, actually)

My guess is the linker isn't setup properly, but I can't find a way to 
fix it? If it couldn't find the freshly installed Gl libraries I could
understand it, I'm missing something obvious...

Google drew a blank - plenty of people reporting that error, but I
couldn't see a fix.

On FreeBSD I used to have to add '-pthread' for GL apps, is there
something similar that needs doing on NetBSD?

Thanks.
-- 
Rasputin :: Jack of All Trades - Master of Nuns