Panic on levity polymorphic very unsafe coerce

{-# LANGUAGE TypeInType #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE MagicHash #-}

module LevityId where

import GHC.Types
import GHC.Prim

levityPolymorphicId :: forall (a :: TYPE r). a -> a
levityPolymorphicId = unsafeCoerce#

  (GHC version 8.3.20170928 for x86_64-apple-darwin):
	runtimeRepPrimRep
  typePrimRep (a_aW0 :: TYPE r_aVZ)
  r_aVZ
  Call stack:
      CallStack (from HasCallStack):
        callStackDoc, called at compiler/utils/Outputable.hs:1144:37 in ghc:Outputable
        pprPanic, called at compiler/simplStg/RepType.hs:358:5 in ghc:RepType
        runtimeRepPrimRep, called at compiler/simplStg/RepType.hs:344:5 in ghc:RepType
        kindPrimRep, called at compiler/simplStg/RepType.hs:307:18 in ghc:RepType
        typePrimRep, called at compiler/simplStg/UnariseStg.hs:666:8 in ghc:UnariseStg

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

As originally mentioned here.

Trac metadata

Trac field	Value
Version	8.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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