Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: wumpus-tree (user goal)
rejecting: wumpus-tree-0.20.0, 0.18.0, 0.17.0, 0.16.0, 0.15.0, 0.14.0, 0.13.0,
0.12.0, 0.11.1 (global constraint requires ==0.11.0)
trying: wumpus-tree-0.11.0
trying: base-4.8.1.0/installed-4f7... (dependency of wumpus-tree-0.11.0)
next goal: wumpus-core (dependency of wumpus-tree-0.11.0)
rejecting: wumpus-core-0.52.1, 0.52.0, 0.51.0, 0.50.0, 0.43.0, 0.42.1, 0.42.0,
0.41.0 (conflict: wumpus-tree => wumpus-core==0.40.0)
rejecting: wumpus-core-0.40.0 (conflict: base==4.8.1.0/installed-4f7...,
wumpus-core => base<4.5)
rejecting: wumpus-core-0.37.0, 0.36.0, 0.35.0, 0.34.0, 0.33.0, 0.32.0, 0.31.0,
0.30.0, 0.23.0, 0.22.0, 0.21.0, 0.20.0, 0.19.0, 0.18.0, 0.17.0, 0.16.0,
0.15.0, 0.14.0, 0.13.1, 0.13.0, 0.12.0 (conflict: wumpus-tree =>
wumpus-core==0.40.0)
Dependency tree exhaustively searched.