Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] trying: spade-0.1.0.9 (user goal)
[__1] next goal: sdl2-ttf (dependency of spade)
[__1] rejecting: sdl2-ttf-2.1.3 (conflict: pkg-config package
SDL2_ttf>=2.0.12, not found in the pkg-config database)
[__1] rejecting: sdl2-ttf-2.1.2 (conflict: spade => sdl2-ttf>=2.1.3 && <2.2)
[__1] skipping: sdl2-ttf-2.1.1, sdl2-ttf-2.1.0, sdl2-ttf-2.0.2,
sdl2-ttf-2.0.1, sdl2-ttf-2.0.0, sdl2-ttf-1.0.0, sdl2-ttf-0.2.2,
sdl2-ttf-0.2.1, sdl2-ttf-0.2.0 (has the same characteristics that caused the
previous version to fail: excluded by constraint '>=2.1.3 && <2.2' from
'spade')
[__1] fail (backjumping, conflict set: sdl2-ttf, spade)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: spade, sdl2-ttf