Update: After clearing out the supplied Wx-widgets 2.5 and re-running config, autoreconf, etc., I ran make again in the XaraLX directory and ran into the same error as before, which I ended up solving with the following kludge:

% sudo ln -s /Users/gpetty/wx/v263/build-unicode-debug/lib/libwx_macud-2.6.0.dylib /usr/local/lib/libwx_macud-2.6.0.dylib

That seemed to work, as make then proceeded to run for a very long time, successfully making several large libraries (kernel, tools, etc.). But then this happened:

ranlib libTools.a
Making all in po
Makefile:431: warning: overriding commands for target `XaraLX.pot-update'
Makefile:155: warning: ignoring old commands for target `XaraLX.pot-update'
Makefile:431: warning: overriding commands for target `XaraLX.pot'
Makefile:184: warning: ignoring old commands for target `XaraLX.pot'
sed -e '/^#/d' remove-potcdate.sin > t-remove-potcdate.sed
mv t-remove-potcdate.sed remove-potcdate.sed
make[1]: *** No rule to make target `../wxOil/xrc/xaralx.po', needed by `XaraLX.pot'. Stop.
make: *** [all-recursive] Error 1

Note that there don't seem to be source code or object files of any kind in ../wxOil/xrc

Any assistance will be greatly appreciated ... I feel I must be getting close.