[GHC] #7862: Could not deduce (A) from the context (A, ...)

[GHC]

#7862: Could not deduce (A) from the context (A, ...)
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              Reporter:  alang9      |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.8.3
  (Type checker)                     |         Keywords:
            Resolution:              |     Architecture:  x86_64 (amd64)
      Operating System:  Linux       |       Difficulty:  Unknown
       Type of failure:  GHC         |       Blocked By:
  rejects valid program              |  Related Tickets:
             Test Case:  indexed-    |
  types/should_compile/T7862         |
              Blocking:              |
Differential Revisions:              |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"2b67b8f9b259c95ef9394c3a8ff801dc00e968d9/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="2b67b8f9b259c95ef9394c3a8ff801dc00e968d9"
 Test Trac #7862
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7862#comment:9>
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