[GHC] #11348: Local open type families instances ignored during type checking

[GHC]

#11348: Local open type families instances ignored during type checking
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        Reporter:  alexvieth         |                Owner:
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1-rc1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by alexvieth):

 Diff created https://phabricator.haskell.org/D1762

 A few tests fail due to a changeup in the order of type errors (since
 instance and tycl decl checking is interleaved). Will need some advice on
 what to do about that.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11348#comment:11>
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