Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: algebra (user goal)
rejecting: algebra-4.3, algebra-4.2, algebra-4.1, algebra-4.0, algebra-3.1,
algebra-3.0.2, algebra-3.0.1.1, algebra-3.0.1, algebra-3.0, algebra-2.1.1.2,
algebra-2.1.1.1, algebra-2.1.1, algebra-2.1, algebra-2.0.7 (constraint from
user target requires ==2.0.6)
trying: algebra-2.0.6
trying: base-4.9.0.0/installed-4.9... (dependency of algebra-2.0.6)
next goal: void (dependency of algebra-2.0.6)
rejecting: void-0.7.1, void-0.7, void-0.6.1, void-0.6 (conflict: algebra =>
void>=0.5.4.3 && <0.6)
rejecting: void-0.5.12, void-0.5.11, void-0.5.10, void-0.5.8, void-0.5.7,
void-0.5.6, void-0.5.5.1, void-0.5.5, void-0.5.4.3 (conflict:
base==4.9.0.0/installed-4.9..., void => base>=3 && <4.8)
rejecting: void-0.5.4.2, void-0.5.4.1, void-0.5.4, void-0.5.3, void-0.5.2,
void-0.5.1, void-0.5.0, void-0.4, void-0.3, void-0.2, void-0.1 (conflict:
algebra => void>=0.5.4.3 && <0.6)
Dependency tree exhaustively searched.