Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] trying: piyo-0.1.0.0 (user goal)
[__1] next goal: sdl2-mixer (dependency of piyo)
[__1] rejecting: sdl2-mixer-1.1.0, sdl2-mixer-0.1 (conflict: pkg-config
package SDL2_mixer>=2.0.0, not found in the pkg-config database)
[__1] fail (backjumping, conflict set: piyo, sdl2-mixer)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: sdl2-mixer, piyo