Can't seem to build python against custom tcl/tk

[Russell E. Owen]

I'm trying to build a non-framework python on MacOS X 10.5 using a
custom tcl/tk that lives in an arbitrary directory. (For complicated
reasons we don't want the system tcl/tk). It is easy to build an X11
tcl/tk this way (and we are content with X11) so I did that.

Unfortunately I can't seem to build Python in such a way that it sees
this tcl/tk.

The only documented way to do this I found was to edit Modules/Setup or
Setup.local, so I did the following:
$ /configure --prefix=/Users/rowen/TestBuild/pythonroot/
--disable-framework
Edit Modules/Setup.local to add this text (based on comments in
Modules/Setup):
_tkinter _tkinter.c tkappinit.c -DWITH_APPINIT \
-L/Users/rowen/TestBuild/tcltkroot/lib \
-I/Users/rowen/TestBuild/tcltkroot/include \
-ltk8.4 -ltcl8.4 \
-I/usr/X11R6/include \
-L/usr/X11R6/lib \
-lX11
$ make
$ make install

This builds, but the resulting python is missing the _tkinter library.

I tried setting CFLAGS:
$ export CFLAGS="-I/Users/rowen/TestBuild/tcltkroot/include
-L/Users/rowen/TestBuild/tcltkroot/bin"
before running configure, but that didn't help.

So...any advice? Any obvious mistake? (I did double-check each path in
the text I added to Setup.local) Is there some way to convince configure
to use my tcl/tk (that would potentially be simpler than editing
Modules/Setup.local).

-- Russell