Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: haddock (user goal)
rejecting: haddock-2.16.1, 2.16.0, 2.15.0.2, 2.15.0.1, 2.15.0, 2.14.3, 2.14.2
(global constraint requires ==2.14.1)
trying: haddock-2.14.1
next goal: base (dependency of haddock-2.14.1)
rejecting: base-4.8.1.0/installed-4f7... (conflict: haddock => base>=4.3 &&
<4.8)
rejecting: base-4.8.1.0, 4.8.0.0, 4.7.0.2, 4.7.0.1, 4.7.0.0, 4.6.0.1, 4.6.0.0,
4.5.1.0, 4.5.0.0, 4.4.1.0, 4.4.0.0, 4.3.1.0, 4.3.0.0, 4.2.0.2, 4.2.0.1,
4.2.0.0, 4.1.0.0, 4.0.0.0, 3.0.3.2, 3.0.3.1 (global constraint requires
installed instance)
Dependency tree exhaustively searched.