Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: algebra (user goal)
rejecting: algebra-4.2, 4.1, 4.0, 3.1, 3.0.2, 3.0.1.1, 3.0.1, 3.0, 2.1.1.2,
2.1.1.1, 2.1.1, 2.1, 2.0.7, 2.0.6 (global constraint requires ==2.0.5)
trying: algebra-2.0.5
trying: base-4.8.1.0/installed-4f7... (dependency of algebra-2.0.5)
next goal: void (dependency of algebra-2.0.5)
rejecting: void-0.7.1, 0.7, 0.6.1, 0.6 (conflict: algebra => void>=0.5.4.3 &&
<0.6)
rejecting: void-0.5.12, 0.5.11, 0.5.10, 0.5.8, 0.5.7, 0.5.6, 0.5.5.1, 0.5.5,
0.5.4.3 (conflict: base==4.8.1.0/installed-4f7..., void => base>=3 && <4.8)
rejecting: void-0.5.4.2, 0.5.4.1, 0.5.4, 0.5.3, 0.5.2, 0.5.1, 0.5.0, 0.4, 0.3,
0.2, 0.1 (conflict: algebra => void>=0.5.4.3 && <0.6)
Dependency tree exhaustively searched.