My fix is simply:

Index: x11/xproto/builtin.mk
===================================================================
RCS file: /cvsroot/pkgsrc/x11/xproto/builtin.mk,v
retrieving revision 1.1
diff -u -r1.1 builtin.mk
--- x11/xproto/builtin.mk	19 Apr 2006 12:19:47 -0000	1.1
+++ x11/xproto/builtin.mk	30 May 2006 19:19:16 -0000
@@ -13,7 +13,7 @@
 ###
 .if !defined(IS_BUILTIN.xproto)
 IS_BUILTIN.xproto=	no
-.  if empty(H_XFUNCPROTO:M__nonexistent__)
+.  if empty(H_XFUNCPROTO:M__nonexistent__) && (${X11BASE} != ${LOCALBASE})
 IS_BUILTIN.xproto=	yes
 .  endif
 .endif


I am not sure if that is the same problem you have.

More details are at 
http://mail-index.netbsd.org/tech-pkg/2006/05/05/0004.html and I never 
received feedback.

The problem is because since it is detected, then the pkg-config 
xproto.pc file is not buildlinked.

Please let me know if that one line change above will allow libICE to 
build for you.

An alternative fix is to have the builtin.mk file generated a xproto.pc 
file just for the buildlinking (such as x11/compositeproto/builtin.mk and 
x11/fixesproto/builtin.mk do).

I think you are using DragonFly. The pkgsrc-wip xorg-server package has 
not been ported to DragonFly nor NetBSD yet. Last week, I committed more 
fixes to upstream xorg so now xorg HEAD xserver does build and work under 
NetBSD, but some more fixes are needed for DragonFly -- in particular 
there is strange behaviour with DragonFly's threads (already discussed 
some on DragonFly lists).


 Jeremy C. Reed

p.s. I have built and used pkgsrc/x11/xorg-server 
using the pkgsrc wip/modular-xorg-libs to provide X11 libraries. That 
should work on DragonFly too. But that is also a work in progress since 
the code for using the wip/modular-xorg-libs as a valid X11_TYPE I have 
not committed.