Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: keys (user goal)
rejecting: keys-3.11, keys-3.10.2, keys-3.10.1, keys-3.10, keys-3.0.4,
keys-3.0.3, keys-3.0.2, keys-3.0.1.1, keys-3.0.1, keys-3.0, keys-2.2,
keys-2.1.3.2, keys-2.1.3.1, keys-2.1.3, keys-2.1.2, keys-2.1.1.1, keys-2.1.1,
keys-2.1, keys-2.0.1, keys-2.0, keys-1.8.0.2, keys-1.8.0.1, keys-1.8.0,
keys-0.3.0, keys-0.2.7, keys-0.2.6, keys-0.2.5, keys-0.2.4, keys-0.2.3,
keys-0.2.2, keys-0.2.1 (constraint from user target requires ==0.1.0.1)
trying: keys-0.1.0.1
next goal: base (dependency of keys-0.1.0.1)
rejecting: base-4.9.0.0/installed-4.9... (conflict: keys => base>=4 && <4.4)
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.