Warning: The install command is a part of the legacy v1 style of cabal usage. Please switch to using either the new project style and the new-install command or the legacy v1-install alias as new-style projects will become the default in the next version of cabal-install. Please file a bug if you cannot replicate a working v1- use case with the new-style commands. For more information, see: https://wiki.haskell.org/Cabal/NewBuild Resolving dependencies... cabal: Could not resolve dependencies: [__0] next goal: taffybar (user goal) [__0] rejecting: taffybar-3.2.2 (conflict: pkg-config package gtk+-3.0-any, not found in the pkg-config database) [__0] rejecting: taffybar-3.2.1, taffybar-3.2.0, taffybar-3.1.2, taffybar-3.1.1, taffybar-3.1.0, taffybar-3.0.0, taffybar-2.1.2, taffybar-2.1.1, taffybar-2.1.0, taffybar-2.0.0, taffybar-1.0.2, taffybar-1.0.1, taffybar-1.0.0, taffybar-0.4.6, taffybar-0.4.5, taffybar-0.4.4, taffybar-0.4.3, taffybar-0.4.2, taffybar-0.4.1, taffybar-0.4.0, taffybar-0.3.0, taffybar-0.2.1, taffybar-0.2.0, taffybar-0.1.3, taffybar-0.1.2, taffybar-0.1.1, taffybar-0.1.0 (constraint from user target requires ==3.2.2) [__0] fail (backjumping, conflict set: taffybar) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: taffybar