[GHC] #4896: Deriving Data does not work for attached code

[GHC]

#4896: Deriving Data does not work for attached code
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              Reporter:  mitar       |            Owner:
                  Type:  bug         |           Status:  infoneeded
              Priority:  low         |        Milestone:  7.10.1
             Component:  Compiler    |          Version:  7.1
            Resolution:              |         Keywords:
      Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:              |       Blocked By:
  None/Unknown                       |  Related Tickets:
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by mitar):

 I don't think that the question is what error message says, but that there
 should not be any errors and that GHC should know how to handle/compile
 this in the first place, no?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4896#comment:9>
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