Resolving dependencies... cabal: Could not resolve dependencies: [__0] next goal: named-servant-server (user goal) [__0] rejecting: named-servant-server-0.1.1 (constraint from user target requires ==0.1.0) [__0] trying: named-servant-server-0.1.0 [__1] next goal: named-servant (dependency of named-servant-server) [__1] rejecting: named-servant-0.1.1 (conflict: named-servant-server => named-servant==0.0.3) [__1] skipping: named-servant-0.0.2, named-servant-0.0.1 (has the same characteristics that caused the previous version to fail: excluded by constraint '==0.0.3' from 'named-servant-server') [__1] fail (backjumping, conflict set: named-servant, named-servant-server) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: named-servant-server, named-servant