Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: cassava (user goal)
rejecting: cassava-0.4.5.1, cassava-0.4.5.0, cassava-0.4.4.0, cassava-0.4.3.1,
cassava-0.4.3.0, cassava-0.4.2.4, cassava-0.4.2.3, cassava-0.4.2.2,
cassava-0.4.2.1, cassava-0.4.2.0, cassava-0.4.1.0, cassava-0.4.0.0,
cassava-0.3.0.1, cassava-0.3.0.0, cassava-0.2.2.0, cassava-0.2.1.2 (constraint
from user target requires ==0.2.1.1)
trying: cassava-0.2.1.1
next goal: base (dependency of cassava-0.2.1.1)
rejecting: base-4.9.0.0/installed-4.9... (conflict: base =>
ghc-prim==0.5.0.0/installed-0.5..., cassava => ghc-prim>=0.2 && <0.4)
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.