Thanks Sidney!
Btw., I managed to get Enigma running with SDL 2, but this required substantial changes to the display code and there are still several issues that I haven't been able to fix yet (fullscreen mode for example, and SDL2 garbles many of the sound effects). In other words, the SDL 2 port probably won't make it into a releasable state within the next few weeks.
Would it make sense to update the official OS X release on
enigma-game.org with the patched version? Or would this potentially break Enigma for users of older versions of OS X? The alternative would be to wait for an updated version of SDL_image and release fixed binaries then.