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] trying: ribbit-0.1.0.0 (user goal) [__1] unknown package: om-show (dependency of ribbit) [__1] fail (backjumping, conflict set: om-show, ribbit) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: ribbit, om-show