[GHC] #13813: DeriveFunctor spuriously rejects existential context with type synonym mentioning the last type variable

[GHC]

#13813: DeriveFunctor spuriously rejects existential context with type synonym
mentioning the last type variable
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.4.1
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  GHC rejects       |            Test Case:
  valid program                      |  deriving/should_compile/T13813
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3635
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by RyanGlScott):

 * testcase:   => deriving/should_compile/T13813
 * status:  patch => closed
 * resolution:   => fixed
 * milestone:   => 8.4.1


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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13813#comment:3>
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