at-spi quartz variant fails to build

[daveh@…]

the at-spi quartz variant fails when compiling:

sudo port install at-spi quartz
---> Building at-spi with target all
Error: Target org.macports.build returned: shell command " cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_gnome_at-spi/work/at-spi-1.22.0" && make all " returned error 2
Command output: make all-recursive
Making all in docs
Making all in reference
Making all in cspi
make[4]: Nothing to be done for `all'.
Making all in idl
make[4]: Nothing to be done for `all'.
make[4]: Nothing to be done for `all-am'.
make[3]: Nothing to be done for `all-am'.
Making all in idl
make[2]: Nothing to be done for `all'.
Making all in libspi
make all-am
make[3]: Nothing to be done for `all-am'.
Making all in login-helper
make all-am
make[3]: Nothing to be done for `all-am'.
Making all in registryd
/usr/bin/gcc-4.0 -DHAVE_CONFIG_H -I. -I.. -I.. -I.. -I../libspi -I../libspi -Wall -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wno-sign-compare -DORBIT2=1 -D_REENTRANT -I/opt/local/include/libbonobo-2.0 -I/opt/local/include/glib-2.0 -I/opt/local/lib/glib-2.0/include -I/opt/local/include -I/opt/local/include/orbit-2.0 -I/opt/local/include/bonobo-activation-2.0 -I/opt/local/include/atk-1.0 -I/opt/local/include/gtk-2.0 -I/opt/local/lib/gtk-2.0/include -I/opt/local/include/cairo -I/opt/local/include/pango-1.0 -I/opt/local/include/freetype2 -I/opt/local/include/libpng12 -I/opt/local/include -O2 -MT desktop.o -MD -MP -MF .deps/desktop.Tpo -c -o desktop.o desktop.c
desktop.c:32:22: error: gdk/gdkx.h: No such file or directory
desktop.c: In function 'spi_atk_desktop_init':
desktop.c:119: warning: implicit declaration of function 'gdk_x11_lookup_xdisplay'
desktop.c:119: warning: nested extern declaration of 'gdk_x11_lookup_xdisplay'
desktop.c:119: warning: implicit declaration of function 'GDK_DISPLAY'
desktop.c:119: warning: nested extern declaration of 'GDK_DISPLAY'
desktop.c:119: warning: assignment makes pointer from integer without a cast
make[2]: * [desktop.o] Error 1
make[1]: * [all-recursive] Error 1
make: * [all] Error 2

Error: Status 1 encountered during processing.