[GHC] #4170: Invalid "duplicate instance" error

[GHC]

#4170: Invalid "duplicate instance" error
-------------------------------------+---------------------------------
        Reporter:  verdelyi          |         Owner:
            Type:  bug               |        Status:  new
        Priority:  low               |     Milestone:  7.6.2
       Component:  Template Haskell  |       Version:  6.12.3
      Resolution:                    |      Keywords:
Operating System:  Unknown/Multiple  |  Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |    Difficulty:
       Test Case:                    |    Blocked By:  4230
        Blocking:                    |
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Comment (by Krzysztof Gogolewski <krz.gogolewski@?>):

 In [changeset:e595c81ee0951f17d34b918123dfa7711710fe89/testsuite]:
 {{{
 #!CommitTicketReference repository="testsuite"
 revision="e595c81ee0951f17d34b918123dfa7711710fe89"
 Add tests for new TH #4124, #4128, #4170, #4364, #6062
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4170#comment:7>
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