Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: gi-gtkosxapplication (user goal)
rejecting: gi-gtkosxapplication-2.0.15 (conflict: requires pkg-config package
gtk-mac-integration-gtk3>=2.0 && <3, not found in the pkg-config database)
rejecting: gi-gtkosxapplication-2.0.14, gi-gtkosxapplication-2.0.13,
gi-gtkosxapplication-2.0.12, gi-gtkosxapplication-2.0.11,
gi-gtkosxapplication-2.0.10, gi-gtkosxapplication-2.0.9,
gi-gtkosxapplication-2.0.8, gi-gtkosxapplication-2.0.7,
gi-gtkosxapplication-2.0.6, gi-gtkosxapplication-2.0.5,
gi-gtkosxapplication-2.0.4 (constraint from user target requires ==2.0.15)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: gi-gtkosxapplication