Crash with data type return kinds
This module
{-# LANGUAGE StandaloneKindSignatures, TypeFamilies, GADTs, DataKinds #-}
module TyCl where
import Data.Kind
type family Star where Star = Type
type W :: Star
type W = T
newtype T where
MkT :: Int -> W
crashes HEAD:
ghc-stage2: panic! (the 'impossible' happened)
(GHC version 8.11.0.20200615:
getRuntimeRep
(Int |> Sym (D:R:Star[0])) :: Star
Call stack:
CallStack (from HasCallStack):
callStackDoc, called at compiler/GHC/Utils/Outputable.hs:1221:37 in ghc:GHC.Utils.Outputable
pprPanic, called at compiler/GHC/Core/Type.hs:2072:18 in ghc:GHC.Core.Type