Resolving dependencies... cabal: Could not resolve dependencies: trying: haddock-api-2.16.0 (user goal) next goal: ghc (dependency of haddock-api-2.16.0) rejecting: ghc-7.8.3/installed-4df... (conflict: haddock-api => ghc>=7.10 && <7.10.2) Dependency tree exhaustively searched.