Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: happindicator (user goal)
rejecting: happindicator-0.0.4 (conflict: requires pkg-config package
appindicator-0.1-any, not found in the pkg-config database)
rejecting: happindicator-0.0.3, happindicator-0.0.2, happindicator-0.0.1
(constraint from user target requires ==0.0.4)
Dependency tree exhaustively searched.