Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: keys (user goal)
rejecting: keys-3.10.2, 3.10.1, 3.10, 3.0.4, 3.0.3, 3.0.2, 3.0.1.1, 3.0.1,
3.0, 2.2, 2.1.3.2, 2.1.3.1, 2.1.3, 2.1.2, 2.1.1.1, 2.1.1, 2.1, 2.0.1, 2.0,
1.8.0.2, 1.8.0.1, 1.8.0, 0.3.0, 0.2.7, 0.2.6, 0.2.5, 0.2.4, 0.2.3, 0.2.2,
0.2.1 (global constraint requires ==0.1.0.1)
trying: keys-0.1.0.1
next goal: base (dependency of keys-0.1.0.1)
rejecting: base-4.8.1.0/installed-4f7... (conflict: keys => base>=4 && <4.4)
rejecting: base-4.8.1.0, 4.8.0.0, 4.7.0.2, 4.7.0.1, 4.7.0.0, 4.6.0.1, 4.6.0.0,
4.5.1.0, 4.5.0.0, 4.4.1.0, 4.4.0.0, 4.3.1.0, 4.3.0.0, 4.2.0.2, 4.2.0.1,
4.2.0.0, 4.1.0.0, 4.0.0.0, 3.0.3.2, 3.0.3.1 (global constraint requires
installed instance)
Dependency tree exhaustively searched.