pkg-config and modular-xorg and dependencies on Solaris 10 11/06 x86 32-bit

[Atticus <grobe0ba%gmail.com@localhost>]

I'm attempting to build modular-xorg on Solaris 10 11/06 x86 32-bit.
I've installed xproto from x11/xproto, my mk.conf sets
X11_TYPE=modular. When attempting to build modular-xorg (or any other
package using X), it fails without being able to find xproto. After
examining the error messages for being unable to find xproto as well
as the config.log for libFS, I've traced the problem (at least
partially) to pkgsrc's invocation of pkg-config. It sets a
PKGCONFIG_LIBDIR, then executes pkg-config with that in it's
environment. WIth it set, it cannot find xproto, or many other
packages. Without it set, pkg-config works like a charm. I've
attempted just patching the .work/bin/pkg-config script to not use it,
but pkgsrc overwrites it when I attempt to build. I've spent at least
6 hours Googling trying to figure this one out, but I couldn't find
anything there. The pkgsrc guide doesn't appear to have any references
to it at all. I'm at a dead end. I'm really hoping to get this working
right, since pkgsrc is working great for everything else on this box.

Thanks in advance,
-- 
FT2(SS) Byron Grobe, USN
USS Providence (SSN-719)