x11/gtk2 "Checks for JPEG loader failed"

[Michael Huff <mphuff%gmail.com@localhost>]

Hi, trying to build gtk2 on solaris 10, using sunstudio 10. I've got everything
built and installed (including jpg) but gtk2 dies during the configure phase
with the following error:

checking for jpeglib.h... no
configure: WARNING: *** JPEG loader will not be built (JPEG header file not
found) ***
configure: error:
*** Checks for JPEG loader failed. You can build without it by passing
*** --without-libjpeg to configure but some programs using GTK+ may
*** not work properly
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/x11/gtk2
*** Error code 1

I've tried playing with CFLAGS, CPPFLAGS and even edited options.mk (to include
--without-libjpeg) and I've gone so far as to pkg_delete tiff and jpeg and
rebuild them; but I still get the same error. 

Can anyone tell me what they think is going wrong and how I can get around this?