Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: vision (user goal)
rejecting: vision-0.0.5.0, 0.0.4.0, 0.0.3.0 (global constraint requires
==0.0.2.4)
trying: vision-0.0.2.4
trying: base-4.8.1.0/installed-4f7... (dependency of vision-0.0.2.4)
trying: MonadCatchIO-mtl-0.3.1.0 (dependency of vision-0.0.2.4)
next goal: MonadCatchIO-transformers (dependency of MonadCatchIO-mtl-0.3.1.0)
rejecting: MonadCatchIO-transformers-0.3.1.3, 0.3.1.2, 0.3.1.1 (conflict:
MonadCatchIO-mtl => MonadCatchIO-transformers==0.3.1.0)
rejecting: MonadCatchIO-transformers-0.3.1.0 (conflict:
base==4.8.1.0/installed-4f7..., MonadCatchIO-transformers => base<4.8)
rejecting: MonadCatchIO-transformers-0.3.0.0, 0.2.2.3, 0.2.2.2, 0.2.2.1,
0.2.2.0, 0.2.1.0, 0.2.0.0, 0.1.0.1, 0.1.0.0, 0.0.2.0, 0.0.1.0 (conflict:
MonadCatchIO-mtl => MonadCatchIO-transformers==0.3.1.0)
Dependency tree exhaustively searched.