#11334: GHC panic when calling typeOf on a promoted data constructor -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: bgamari Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler (Type | Version: 8.0.1-rc1 checker) | Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1757 Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): This fails, {{{#!hs {-# LANGUAGE DataKinds #-} import Data.Typeable import Data.Functor.Compose main :: IO () main = print $ typeOf (undefined :: Proxy 'Compose) }}} with a compiler panic due to `TcInteract.mk_typeable_pred` calling `typeKind` on an ill-kinded type, `TYPE 'Lifted (TYPE 'Lifted *) -> Compose * * *`. Note the application `TYPE 'Lifted (TYPE 'Lifted *)`, which oversaturates `TYPE`. The problem here is apparently that the kind variables of `Compose` are all instantiated with `*` with `-XNoPolyKinds` I haven't yet determined where this occurs. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11334#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler