fonts/harfbuzz fails to build saying can't find ft2build.h

["J. Lewis Muir" <jlmuir%imca-cat.org@localhost>]

I'm trying to build fonts/harfbuzz on Mac OS X Mavericks (10.9) for
x86_64 Darwin from pkgsrc 2014Q1, and it's failing saying it can't find
ft2build.h:

===
[snip]
  CXX      libharfbuzz_la-hb-fallback-shape.lo
  CXX      libharfbuzz_la-hb-glib.lo
  CXX      libharfbuzz_la-hb-ft.lo
In file included from hb-ft.cc:30:
./hb-ft.h:32:10: fatal error: 'ft2build.h' file not found
#include <ft2build.h>
         ^
1 error generated.
gnumake[4]: *** [libharfbuzz_la-hb-ft.lo] Error 1
gnumake[3]: *** [all-recursive] Error 1
gnumake[2]: *** [all] Error 2
gnumake[1]: *** [all-recursive] Error 1
gnumake: *** [all] Error 2
*** Error code 2

Stop.
bmake: stopped in /pkgsrc/fonts/harfbuzz
*** Error code 1

Stop.
bmake: stopped in /pkgsrc/fonts/harfbuzz
===

I have XQuartz installed in /opt/X11 (the normal place).  I have
confirmed that ft2build.h is in /opt/X11/include/freetype2.  I do not
have freetype2 installed from pkgsrc; I'm expecting harfbuzz to use the
native version installed with XQuartz under /opt/X11.  This seems to
be working correctly since harfbuzz does not try to pull in freetype2
from pkgsrc as a dependency.  I have also confirmed that the -I include
option for the freetype2 include directory is making it to the compile
line that is failing.  I did this by editing the Makefile to print out
exactly what it will execute.  The result was:

===
EXECUTING /bin/sh ../libtool --silent --tag=CXX --mode=compile clang++ 
-DHAVE_CONFIG_H -I. -I.. -D_THREAD_SAFE -D_REENTRANT 
-I/pkg/include/glib/glib-2.0 -I/pkg/lib/glib-2.0/include -I/pkg/include 
-I/opt/X11/include/freetype2 -I/pkg/include -I/usr/include 
-I/opt/X11/include/freetype2 -pipe -O2 -I/pkg/include -I/usr/include 
-I/opt/X11/include/freetype2 -fno-rtti -fno-exceptions -Wcast-align 
-fvisibility-inlines-hidden --std=c++0x -MT libharfbuzz_la-hb-ft.lo -MD -MP -MF 
.deps/libharfbuzz_la-hb-ft.Tpo -c -o libharfbuzz_la-hb-ft.lo hb-ft.cc
  CXX      libharfbuzz_la-hb-ft.lo
In file included from hb-ft.cc:30:
./hb-ft.h:32:10: fatal error: 'ft2build.h' file not found
#include <ft2build.h>
         ^
1 error generated.
===

Any suggestions for how to fix this?

Thanks!

Lewis