GHC panic (No skolem info)
If you compile this program using commit 0d0c9019:
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE StandaloneKindSignatures #-}
{-# LANGUAGE TypeFamilies #-}
module Bug where
import Data.Kind
import GHC.Exts
type F1 :: forall k -> k
type family F1 k :: k
type F2 :: forall k -> k
type F2 = F1
You'll get this panic:
[1 of 1] Compiling Bug ( Bug.hs, Bug.o )
ghc-stage2: panic! (the 'impossible' happened)
(GHC version 8.11.0.20200831:
No skolem info:
[t_ahL]
Call stack:
CallStack (from HasCallStack):
callStackDoc, called at compiler/GHC/Utils/Panic.hs:185:37 in ghc:GHC.Utils.Panic
pprPanic, called at compiler/GHC/Tc/Errors.hs:2813:17 in ghc:GHC.Tc.Errors