[GHC] #12427: Type inference regression with RankNTypes (GHC 8.1)

[GHC]

#12427: Type inference regression with RankNTypes (GHC 8.1)
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        Reporter:  thomie            |                Owner:
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.2.1
       Component:  Compiler (Type    |              Version:  8.1
  checker)                           |
      Resolution:                    |             Keywords:  RankNTypes
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #12431            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 No don't bother, thank you! I'm on this: `wip/spj-tc-branch`.  (But I'm
 heavily distracted at the moment.)

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12427#comment:5>
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