[GHC] #15599: typeclass inference depends on whether a module is exposed.

[GHC]

#15599: typeclass inference depends on whether a module is exposed.
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        Reporter:  gleachkr          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.2.3
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 There's a big indirection through stack and cabal here.   e.g. how exactly
 this command invoke GHC, and what files exist at that moment?
 {{{
 echo "test" | stack repl src/Tests/Good.hs -- 2> /dev/null | grep
 checkFlag
 }}}
 Would it be possible to explain how to repro by one or more invocations of
 GHC directly?  Thanks

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15599#comment:1>
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