Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: pretty-show (user goal)
rejecting: pretty-show-1.6.12, pretty-show-1.6.11, pretty-show-1.6.10,
pretty-show-1.6.9, pretty-show-1.6.8.2, pretty-show-1.6.8.1,
pretty-show-1.6.8, pretty-show-1.6.7, pretty-show-1.6.6, pretty-show-1.6.5,
pretty-show-1.6.3, pretty-show-1.6.2, pretty-show-1.6.1, pretty-show-1.6,
pretty-show-1.5, pretty-show-1.4.1, pretty-show-1.3.2, pretty-show-1.3.1
(constraint from user target requires ==1.3)
trying: pretty-show-1.3
next goal: base (dependency of pretty-show-1.3)
rejecting: base-4.9.0.0/installed-4.9... (conflict: pretty-show => base<4.3)
rejecting: base-4.9.0.0, base-4.8.2.0, base-4.8.1.0, base-4.8.0.0,
base-4.7.0.2, base-4.7.0.1, base-4.7.0.0, base-4.6.0.1, base-4.6.0.0,
base-4.5.1.0, base-4.5.0.0, base-4.4.1.0, base-4.4.0.0, base-4.3.1.0,
base-4.3.0.0, base-4.2.0.2, base-4.2.0.1, base-4.2.0.0, base-4.1.0.0,
base-4.0.0.0, base-3.0.3.2, base-3.0.3.1 (constraint from non-upgradeable
package requires installed instance)
Dependency tree exhaustively searched.