Yes and no: without this change tapdisk doesn't compile. I believe this is an issue unrelated to this pull request, but I don't really know why we didn't run into it earlier. The problem is that these symbols were put in tapdisk2.c where main() lives, but tapdisk2.c is not compiled into libtapdisk so these symbols are not defined when libtapdisk is compiled. Shall I created a separate PR for this issue?