Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: haddock-api (user goal)
rejecting: haddock-api-2.16.1 (global constraint requires ==2.16.0)
trying: haddock-api-2.16.0
next goal: ghc (dependency of haddock-api-2.16.0)
rejecting: ghc-7.10.2/installed-a64... (conflict: haddock-api => ghc>=7.10 &&
<7.10.2)
Dependency tree exhaustively searched.