Justyouwait.ogg wasn't installed on case-sensitive systems, due to a case typo in the CMakeLists. Thanks to TheMadCharles and Wuzzy for noticing.
#ifndef _SDLname_h_
#define _SDLname_h_
#if defined(__STDC__) || defined(__cplusplus)
#define NeedFunctionPrototypes 1
#endif
#define SDL_NAME(X) SDL_##X
#endif /* _SDLname_h_ */