Klugier, I'm modifying a few scripts in Scripts directory. That way, U++ will build out of the box on BSD distributions.
But I still have a big problem: the need to fix Makefile generation with umk.

For now on, I do a manual fix with before running make:

sed -i -e 's|\$\$|$$$$|g' uppsrc/Makefile.in

I don't know how to fix umk. It needs to not just duplicate but quadruplicate the '$' character found in file names when it creates Makefile.

static String MakeSourcePath(const Vector<String>& dirs, String fn, bool raw, bool exporting)