[GHC] #13988: GADT constructor with kind equality constraint quantifies unused existential type variables

[GHC]

#13988: GADT constructor with kind equality constraint quantifies unused
existential type variables
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3872
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by RyanGlScott):

 * status:  new => patch
 * differential:   => Phab:D3872


Comment:

 I ended up needing to fix this as a part of an unrelated patch,
 Phab:D3872. (Note that I borrowed the solution for this particular issue
 from Richard, so the credit should go to him.)

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13988#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler