[GHC] #11435: Evidence from TC Plugin triggers core-lint warning

[GHC]

#11435: Evidence from TC Plugin triggers core-lint warning
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        Reporter:  jbracker          |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.2
      Resolution:                    |             Keywords:  core-lint
                                     |  warning evidence type-checker
                                     |  plugin
Operating System:  Linux             |         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 goldfire):

 This thread sheds some light: https://mail.haskell.org/pipermail/ghc-
 devs/2015-November/010513.html  Given that this ticket is the same issue
 as the one you raised there, it would be helpful for you to include that
 link when posting.

 I notice that the problem occurs in the result of the simplifier. Could it
 be coercion optimization? Try with `-fno-opt-coercion`. Also, try with
 `-O0`. Does `-fprint-explicit-kinds -fprint-explicit-foralls` change the
 output? The report is made against GHC 7.10.2. Is that accurate? Has
 anyone reproduced with HEAD?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11435#comment:1>
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