[GHC] #11152: GND accepts ill-roled coercion when manually defining it won't typecheck

[GHC]

#11152: GND accepts ill-roled coercion when manually defining it won't typecheck
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        Reporter:  RyanGlScott       |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  7.10.2
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC accepts       |  Unknown/Multiple
  invalid program                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by rwbarton):

 Well, I suppose there is still a bug in that the derived instance is not
 valid Haskell source as displayed, but there are other issues with it
 already (like the use of the qualified name `CoerceJoin.join`).

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11152#comment:2>
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