Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: gtk3 (user goal)
rejecting: gtk3-0.14.6, gtk3-0.14.5, gtk3-0.14.4, gtk3-0.14.3, gtk3-0.14.2,
gtk3-0.14.1, gtk3-0.14.0, gtk3-0.13.9, gtk3-0.13.8, gtk3-0.13.7, gtk3-0.13.6,
gtk3-0.13.4, gtk3-0.13.3, gtk3-0.13.2, gtk3-0.13.1, gtk3-0.13.0.3,
gtk3-0.13.0.2, gtk3-0.13.0.1, gtk3-0.13.0.0, gtk3-0.12.5.7, gtk3-0.12.5.6,
gtk3-0.12.5.5, gtk3-0.12.5.4, gtk3-0.12.5.3, gtk3-0.12.5.2 (constraint from
user target requires ==0.12.5.1)
rejecting: gtk3-0.12.5.1 (conflict: gtk3 => gtk3==0.12.5.0)
rejecting: gtk3-0.12.5.0 (constraint from user target requires ==0.12.5.1)
Dependency tree exhaustively searched.