[GHC] #14892: Field imposters with DuplicateRecordFields and NamedFieldPuns.

[GHC]

#14892: Field imposters with DuplicateRecordFields and NamedFieldPuns.
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        Reporter:  philderbeast      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.4.1-alpha3
      Resolution:                    |             Keywords:  ORF
Operating System:  MacOS X           |         Architecture:  x86_64
 Type of failure:  GHC accepts       |  (amd64)
  invalid program                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #13644            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by adamgundry):

 I think you want `DisambiguateRecordFields`. Without it, the 8.4 behaviour
 is correct, isn't it? Indeed `G.X` does not have a field `x` in scope
 (although it does have `G.x`). The error message could be better, perhaps
 suggesting `DisambiguateRecordFields`.

 Note that `DuplicateRecordFields` implies `DisambiguateRecordFields`,
 which is why enabling the former fixes the problem.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14892#comment:5>
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