[GHC] #13102: orphan family instances can leak through the EPS in --make mode

[GHC]

#13102: orphan family instances can leak through the EPS in --make mode
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        Reporter:  rwbarton          |                Owner:  rwbarton
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by ezyang):

 I don't think it's good to read too much into what Haskell'98 says should
 be the set of visible instances; after all, Haskell'98 doesn't formalize
 overloaded syntax.

 There are a few possible ways to adjust the semantics, but one possibility
 is to say that if the renamer inserts a reference directly to something
 (that wasn't imported), that implicitly imports the module that provided
 that original name. This might be annoying to implement, but anything
 along these lines should be OK? (Certainly, it's what I would expect!)

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13102#comment:14>
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