The current SDL2_mixer OS X runtime (2.0.0 - http://www.libsdl.org/projects/SDL_mixer/release/SDL2_mixer-2.0.0.dmg) contains an smpeg2 that links to the SDL2 framework using @executable_path/…/Frameworks instead of @rpath.
This seems to prevent my application (unix executable) to be shipped like this:
MyExe/
|- MyExe
|- Frameworks/
|-- SDL2.framework
|-- SDL2_mixer.framework
I could only solve this by removing that smpeg2 from the SDL2_mixer.framework I’d distribute.