#12546: GeneralizedNewtypeDeriving produces error messages with incorrect kind signatures -------------------------------------+------------------------------------- Reporter: lexi.lambda | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by mniip): Looks like it tries to unify `k -> Constrant ~ * -> (* -> *) -> Constraint`. It zonks `k ~ *` and then fails with `(* -> *) -> Constraint ~ Constraint`, and the `k = *` leaks into the error message -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12546#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler