[GHC] #15852: Bad axiom produced for polykinded data family

[GHC]

#15852: Bad axiom produced for polykinded data family
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        Reporter:  goldfire          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.7
      Resolution:                    |             Keywords:  TypeFamilies,
                                     |  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by goldfire):

 My pointing to `pprCoAxiom` was from its use in `TcRnDriver.ppr_tycons`.
 Given the appearance of `"COERCION AXIOMS"` in `ppr_tycons`, I thought it
 was what produced the output I saw, which also contains that string. Maybe
 I missed a beat somewhere, but I think you may be barking up the wrong
 tree.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15852#comment:4>
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