Ok. I have fixed the problem. It has to do with libtool having a
hardwired lib search path of /lib /usr/lib and /usr/local/lib,
which in the cross-compile case, is incorrect. I modified the generated
libtool script contained in the project dir,
modifying the sys_lib_search_path_spec so it contained *only* the
target's lib dirs. note that this gets defined twice in the library
for some reason.
To top things off, and make sure there weren't any collisions, I took
out all the *.la files in lib folders around my system (I stored them in
a backup heirarchy).
Cleaned and rebuilt, and voila, things link properly.