[GHC] #10646: Adding GADTs extension makes RankNTypes code fail to compile.

[GHC]

#10646: Adding GADTs extension makes RankNTypes code fail to compile.
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        Reporter:  phadej            |                   Owner:
            Type:  bug               |                  Status:  closed
        Priority:  normal            |               Milestone:
       Component:  Compiler (Type    |                 Version:  7.10.1
  checker)                           |                Keywords:
      Resolution:  invalid           |            Architecture:
Operating System:  Unknown/Multiple  |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by phadej):

 Thanks to you for the explanation!

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10646#comment:3>
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