Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: ghc-events (user goal)
rejecting: ghc-events-0.4.4.0, ghc-events-0.4.3.0, ghc-events-0.4.2.0,
ghc-events-0.4.0.1 (constraint from user target requires ==0.4.0.0)
trying: ghc-events-0.4.0.0
trying: base-4.9.0.0/installed-4.9... (dependency of ghc-events-0.4.0.0)
next goal: array (dependency of ghc-events-0.4.0.0)
rejecting: array-0.5.1.1/installed-0.5..., array-0.5.1.1, array-0.5.1.0,
array-0.5.0.0 (conflict: ghc-events => array>=0.2 && <0.5)
rejecting: array-0.4.0.1 (conflict: base==4.9.0.0/installed-4.9..., array =>
base>=4.2 && <4.7)
rejecting: array-0.4.0.0 (conflict: base==4.9.0.0/installed-4.9..., array =>
base>=4.2 && <4.6)
rejecting: array-0.3.0.3 (conflict: base==4.9.0.0/installed-4.9..., array =>
base>=4.2 && <4.5)
rejecting: array-0.3.0.2, array-0.3.0.1 (conflict:
base==4.9.0.0/installed-4.9..., array => base>=4.2 && <4.4)
rejecting: array-0.3.0.0 (conflict: base==4.9.0.0/installed-4.9..., array =>
base>=3 && <4.4)
rejecting: array-0.2.0.0 (conflict: base==4.9.0.0/installed-4.9..., array =>
base<4.3)
rejecting: array-0.1.0.0 (conflict: ghc-events => array>=0.2 && <0.5)
Dependency tree exhaustively searched.