automake failure - why?

[Yotam Medini]

Using: 

export CONFFLAGS="--disable-GL --disable-glx --disable-aiglx --disable-glx-tls --disable-dri --disable-xgl"
./util/modular/build.sh /home/yotam/xorg/modular -D -c -r xserver/xorg

I now get:

....
GL/glx/Makefile.am: installing `./depcomp'
SUBDIRS: variable `CFB16_DIR' is used but `CFB16_DIR' is undefined
Xprint/Makefile.am: installing `./compile'
Use of uninitialized value in hash element at /home/yotam/xorg/modular/bin/automake.real line 1241.
Use of uninitialized value in list assignment at /home/yotam/xorg/modular/share/automake-1.7/Automake/Channels.pm line 453.
automake: unused variable: `DRI_SOURCES'
autoreconf: automake failed with exit status: 1

Any hint?
-- yotam