[GHC] #9725: Constraint deduction failure

[GHC]

#9725: Constraint deduction failure
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        Reporter:  heisenbug         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  7.8.3
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by RyanGlScott):

 I'm arriving at this bug quite late, but it appears that
 https://ghc.haskell.org/trac/ghc/attachment/ticket/9725/9725.hs works on
 GHC 8.0.1 and later without a hitch. Perhaps it's time to consider this
 bug fixed?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9725#comment:17>
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