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

[GHC]

#15343: Implicitly quantifying a kind variable causes GHC 8.6 to panic
(coercionKind)
-------------------------------------+-------------------------------------
        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:                    |
-------------------------------------+-------------------------------------

Comment (by simonpj):

 I'm on this. It turns out to be a very dark corner.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15343#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler