GHC panic using visible kind applications and a higher-rank kind
Using visible kind applications (#12045 (closed)):
{-# Language LiberalTypeSynonyms #-}
{-# Language PolyKinds #-}
{-# Language RankNTypes #-}
{-# Language DataKinds #-}
import Data.Kind
type Cat ob = ob -> ob -> Type
data Zero :: forall (cat :: forall xx. xx -> Type) a. forall b. Cat (forall b. cat b u)
$ ghci -ignore-dot-ghci 546_bug.hs
GHCi, version 8.7.20181017: http://www.haskell.org/ghc/ :? for help
[1 of 1] Compiling Main ( 546_bug.hs, interpreted )
ghc-stage2: panic! (the 'impossible' happened)
(GHC version 8.7.20181017 for x86_64-unknown-linux):
ASSERT failed!
Type-correct unfilled coercion hole {co_a1yl}
Call stack:
CallStack (from HasCallStack):
callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable
pprPanic, called at compiler/utils/Outputable.hs:1219:5 in ghc:Outputable
assertPprPanic, called at compiler/typecheck/TcHsSyn.hs:1805:99 in ghc:TcHsSyn
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
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