Apparently, I finally managed to fix OpenBabel so that the test-suite can be run from a build-dir, too. In the end, I had to revert to C++ (looking up stuff in my book), a complete defeat for my C skills.

At least the last show-stopper for 1.100.2 (from my perspective) has now been fixed. This release should really be pushed out now, this header-bug has been left unfixed for a couple of months too long.