[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 scottgw):

 That sounds like a reasonable approach: I checked with a (probably
 insufficient) regex on the latest Hackage archive and there are indeed not
 many (~90) packages that appear to write an instance by hand for
 {{{Typeable}}}.

 Out of curiosity is there guidance on when/how to introduce breaking
 changes in GHC?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8132#comment:11>
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