hi
$ uname -a
Linux box 4.8.17-tinycore #2017 SMP Sun Mar 5 15:49:22 UTC 2017 i686 GNU/Linux
the version I think is 8.0? couple releases back.. how do I confirm?
Tested a hypothesis that the experiments with different PNG versions could be the culprit, by checking ldd on the executable and, sure enough, it was linking to libpng12.. I rebooted and tried loading only 16 and it is now linking to that but still same complaint (libpng, png-bin and dev, are all loaded).
As an aside, though I don't think this is causing any problems (yet) is ldd now suggests a similar problem with SDL2, since it is linking to sdl1.2. However I cannot resolve this the same way, because the program needs SDL_Image, which is bundled together with all the other ones in SDL1.2.