Why is "pangocairo" not built?

[skip pobox com]

I'm struggling to get gtk 2.10.6 configured and built.  I've narrowed the
problem down to the pangocairo lib not being built and am focusing on the
pango configure.  Details about my setup:

    OS, compiler: Solaris 10, gcc 3.4
    Pango: 1.14.7
    Cairo: 1.2.4

I set PKG_CONFIG_PATH like so:

    /opt/app/nonc++/glib-2.12/lib/pkgconfig:\
    /opt/app/nonc++/freetype-2.1/lib/pkgconfig:\
    /opt/app/nonc++/xrender-0.8/lib/pkgconfig:\
    /opt/app/nonc++/libpng-1.2/lib/pkgconfig:\
    /opt/app/nonc++/fontconfig-2.2/lib/pkgconfig:\
    /opt/app/nonc++/cairo-1.2/lib/pkgconfig

and configure like so:

    ./configure CC=/opt/app/g++lib6/gcc-3.4/bin/gcc \
    --prefix=/opt/app/nonc++/pango-1.14 --with-dynamic-modules=no

I use --with-dynamic-modules=no because I'm trying to avoid compiling the
arabic module, which currently fails for me.

When configuring Pango, I get this output related to Cairo:

    checking for CAIRO... yes
    checking for cairo_surface_write_to_png in -lcairo... yes
    checking for cairo_ps_surface_create in -lcairo... yes
    checking for cairo_pdf_surface_create in -lcairo... yes
    checking for cairo_xlib_surface_create in -lcairo... yes
    checking for cairo_win32_scaled_font_select_font in -lcairo... no
    checking for cairo_ft_scaled_font_lock_face in -lcairo... yes
    checking for cairo_atsui_font_face_create_for_atsu_font_id in -lcairo... no
    ...
    config.status: creating pangocairo.pc
    ...
    config.status: creating pangocairo-uninstalled.pc
    ...
    configuration:
            backends: X

I don't understand why the cairo backend isn't configured and can't follow
the somewhat arcane logic in the configure script.  In configure.in I see

    PKG_CHECK_MODULES(CAIRO, cairo >= 1.2.2, have_cairo=true, :)

which looks straightforward enough.  I do have Cairo 1.2.4 installed, it's
mentioned in PKG_CONFIG_PATH and has you can see from the configure output,
the configure script agrees that Cairo is available.

So why isn't the pangocairo lib built?

-- 
Skip Montanaro - skip pobox com - http://www.mojam.com/
"The hippies and the hipsters did some great stuff in the sixties,
but the geeks pulled their weight too." -- Billy Bragg