[GHC] #8132: Warning for Typeable instances misplaced

[GHC]

#8132: Warning for Typeable instances misplaced
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        Reporter:  scottgw                       |            Owner:
            Type:  bug                           |  dreixel
        Priority:  normal                        |           Status:  new
       Component:  Compiler                      |        Milestone:
      Resolution:                                |          Version:  7.7
Operating System:  Unknown/Multiple              |         Keywords:
 Type of failure:  Incorrect warning at          |     Architecture:
  compile-time                                   |  Unknown/Multiple
       Test Case:                                |       Difficulty:
        Blocking:                                |  Unknown
                                                 |       Blocked By:
                                                 |  Related Tickets:
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Comment (by dreixel):

 Replying to [comment:3 simonpj]:
 > I think we should turn the warning into an error.

 But that breaks backwards compatibility in a serious way. Lots of code
 lying around gives manual `Typeable` instances right now, especially
 because that's the only way to define such instances in some cases.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8132#comment:4>
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