Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: ghc-events (user goal)
rejecting: ghc-events-0.4.4.0, 0.4.3.0, 0.4.2.0, 0.4.0.1, 0.4.0.0, 0.3.0.1,
0.2.0.1, 0.2, 0.1.0.2 (global constraint requires ==0.1.0.1)
trying: ghc-events-0.1.0.1
trying: base-4.8.1.0/installed-4f7... (dependency of ghc-events-0.1.0.1)
next goal: containers (dependency of ghc-events-0.1.0.1)
rejecting: containers-0.5.6.2/installed-2de..., 0.5.6.3, 0.5.6.2, 0.5.6.1,
0.5.6.0, 0.5.5.1, 0.5.5.0, 0.5.4.0, 0.5.3.1, 0.5.3.0, 0.5.2.1, 0.5.2.0,
0.5.1.0, 0.5.0.0, 0.4.2.1, 0.4.2.0, 0.4.1.0, 0.4.0.0 (conflict: ghc-events =>
containers>=0.2 && <0.4)
rejecting: containers-0.3.0.0 (conflict: base==4.8.1.0/installed-4f7...,
containers => base>=4.2 && <4.7)
rejecting: containers-0.2.0.1, 0.2.0.0 (conflict:
base==4.8.1.0/installed-4f7..., containers => base<4.7)
rejecting: containers-0.1.0.1, 0.1.0.0 (conflict: ghc-events =>
containers>=0.2 && <0.4)
Dependency tree exhaustively searched.