Bug#909740: I am guessing #909740 is what is stopping from having a libsdl2-mixer-dev transition

[Fabian Greffrath]

Hi shirish,

one does not simply transition from sdl1.2-mixer to sdl2-mixer!

For sdl2-mixer you need sdl2 first and porting from sdl1.2 to sdl2 is a 
major rework that is highly non-trivial for many packages.

So, you either have sdl1.2 with sdl1.2-mixer or you have sdl2 with 
sdl2-mixer, but the mogration from the former to the latter requires a 
lot of porting work.

  - Fabian