Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: Bang (user goal)
rejecting: Bang-0.1.1.1, 0.1.1.0, 0.1.0.6, 0.1.0.4, 0.1.0.3 (global constraint
requires ==0.1.0.2)
trying: Bang-0.1.0.2
next goal: bifunctors (dependency of Bang-0.1.0.2)
rejecting: bifunctors-5.1, 5 (conflict: Bang => bifunctors>=4 && <5)
trying: bifunctors-4.2.1
next goal: semigroupoids (dependency of bifunctors-4.2.1)
rejecting: semigroupoids-5.0.0.4, 5.0.0.3, 5.0.0.2, 5.0.0.1, 5 (conflict:
bifunctors => semigroupoids==4.*)
trying: semigroupoids-4.3
trying: transformers-compat-0.4.0.4 (dependency of semigroupoids-4.3)
trying: transformers-compat-0.4.0.4:-two
trying: transformers-compat-0.4.0.4:-three
next goal: transformers (dependency of Bang-0.1.0.2)
rejecting: transformers-0.4.2.0/installed-21d..., 0.4.3.0, 0.4.2.0, 0.4.1.0
(conflict: Bang => transformers>=0.3 && <0.4)
rejecting: transformers-0.3.0.0 (conflict: transformers-compat-0.4.0.4:three
=> transformers>=0.4.1 && <0.5)
rejecting: transformers-0.2.2.1, 0.2.2.0, 0.2.1.0, 0.2.0.0, 0.1.4.0, 0.1.3.0,
0.1.1.0, 0.1.0.1, 0.1.0.0, 0.0.1.0, 0.0.0.0, 0.4.0.0 (conflict: Bang =>
transformers>=0.3 && <0.4)
Dependency tree exhaustively searched.