Re: [GHC] #15343: Implicitly quantifying a kind variable causes GHC 8.6 to panic (coercionKind)

4 Jul 2018

      #15343: Implicitly quantifying a kind variable causes GHC 8.6 to panic
(coercionKind)
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.6.1
       Component:  Compiler (Type    |              Version:  8.5
  checker)                           |
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by monoidal):

 Simplification:

 {{{
 #!hs
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeInType #-}
 module Bug where

 import Data.Kind

 elimSing :: forall (p :: forall z. z). p
 elimSing = undefined

 data WhySym :: Type -> Type

 hsym = elimSing @WhySym
 }}}

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15343#comment:3
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