[GHC] #9071: Panic with -XDeriveFunctor when deriving from a non-Functor in a separate module

[GHC]

#9071: Panic with -XDeriveFunctor when deriving from a non-Functor in a separate
module
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        Reporter:  bens                          |            Owner:
            Type:  bug                           |           Status:  new
        Priority:  normal                        |        Milestone:  7.8.3
       Component:  Compiler                      |          Version:  7.8.2
      Resolution:                                |         Keywords:
Operating System:  Unknown/Multiple              |     Architecture:
 Type of failure:  Compile-time crash            |  Unknown/Multiple
       Test Case:  deriving/should_fail/T9071,   |       Difficulty:
  T9071_2                                        |  Unknown
        Blocking:                                |       Blocked By:
                                                 |  Related Tickets:
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Comment (by simonpj):

 Reid, thanks. Can you identify the "leftover debugging output" and/or
 offer a patch?  Ta

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9071#comment:10>
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