Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: ghci-haskeline (user goal)
rejecting: ghci-haskeline-0.2 (constraint from user target requires ==0.1.1)
trying: ghci-haskeline-0.1.1
next goal: ghc (dependency of ghci-haskeline-0.1.1)
rejecting: ghc-8.0.1.20161018/installed-8.0... (conflict: ghci-haskeline =>
ghc>=6.10.2 && <6.11 || >=6.9 && <6.10.2)
Dependency tree exhaustively searched.