Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: bitset (user goal)
rejecting: bitset-1.4.8, 1.4.7, 1.4.6, 1.4.5, 1.4.4, 1.4.3 (global constraint
requires ==1.4.2)
trying: bitset-1.4.2
next goal: base (dependency of bitset-1.4.2)
rejecting: base-4.7.0.1/installed-e4b... (conflict: bitset => base>=4.4.0 &&
<4.7)
rejecting: base-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.