Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: relative-date (user goal)
rejecting: relative-date-0.0.1 (global constraint requires ==0.0.0)
trying: relative-date-0.0.0
trying: base-4.8.1.0/installed-4f7... (dependency of relative-date-0.0.0)
next goal: datetime (dependency of relative-date-0.0.0)
rejecting: datetime-0.3.1, 0.3.0, 0.2.1 (conflict: relative-date =>
datetime==0.2)
rejecting: datetime-0.2 (conflict: base==4.8.1.0/installed-4f7..., datetime =>
base>=2 && <4)
rejecting: datetime-0.1 (conflict: relative-date => datetime==0.2)
Dependency tree exhaustively searched.