[GHC] #8338: Incoherent instances without -XIncoherentInstances

[GHC]

#8338: Incoherent instances without -XIncoherentInstances
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              Reporter:  goldfire    |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.6.3
            Resolution:              |         Keywords:
      Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:              |       Blocked By:
  None/Unknown                       |  Related Tickets:  #2356
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by goldfire):

 No, #7296 is unrelated. This ticket is all about GHC's lazy overlap check,
 while #7296 is a puzzling behavior introduced by considering overlap
 differently when type-checking an instance method.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8338#comment:6>
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