Maybe you've used --target=i386-linux or something like this?
Yes, removing that solves the problems and does not cause any others. Since this application is a "compiler", --build and --host are enough. I was following the example of the existing Makefile fragments in the buildroot, but they were unnecessarily specifying --target.
Anyway you can complain to Joe's maintainer(s). I can't see any reason to use AC_CANONICAL_TARGET in its configure.ac, and removing this macro should avoid any problem like yours.
I removed all three AC_CANONICAL_* macro calls before removing --target, but this did not seem to change anything. Going back to the as-distributed configure script and not specifying --target has worked fine.
Thanks for the help Alexandre.
