I'm trying to build gtk2, but it seems quite unhappy about not finding 
libX11:

checking for X... libraries /usr/pkg/xorg/lib, headers /usr/pkg/xorg/include
checking for gethostbyname... yes
checking for connect... yes
checking for remove... yes
checking for shmat... yes
checking for IceConnectionNumber in -lICE... yes
checking for XOpenDisplay in -lX11... no
configure: error: *** libX11 not found. Check 'config.log' for more details.
*** Error code 1

Stop.

You'll notice that it knows I have xorg installed, and libX11.so 
certainly exists in /usr/pkg/xorg/lib:

[ root@sorrow - /usr/pkgsrc/x11/gtk2 ]: ls -l /usr/pkg/xorg/lib/libX11.*
-rw-r--r--  1 root  wheel  1318984 Nov  8 08:01 /usr/pkg/xorg/lib/libX11.a
lrwxr-xr-x  1 root  wheel       11 Nov  8 08:01 
/usr/pkg/xorg/lib/libX11.so -> libX11.so.6
lrwxr-xr-x  1 root  wheel       13 Nov  8 08:01 
/usr/pkg/xorg/lib/libX11.so.6 -> libX11.so.6.2
-rwxr-xr-x  1 root  wheel   875577 Nov  8 08:01 
/usr/pkg/xorg/lib/libX11.so.6.2

Any ideas how I can get this to build?

Adam