Resolving dependencies...
cabal: Could not resolve dependencies:
trying: haddock-api-2.17.2 (user goal)
next goal: ghc (dependency of haddock-api-2.17.2)
rejecting: ghc-7.10.3/installed-a78... (conflict: haddock-api => ghc>=8.0 &&
<8.2)
Dependency tree exhaustively searched.