[GHC] #12529: Error message: visible type application of constructor/variable that is not in scope

[GHC]

#12529: Error message: visible type application of constructor/variable that is not
in scope
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        Reporter:  Iceland_jack      |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
                                     |  TypeApplications
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  warning at compile-time            |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by lexi.lambda):

 I recently ran into this, too. It’s definitely extremely confusing, since
 usually identifiers that aren’t in scope are ''very'' clearly indicated in
 error messages, but nothing in these errors would suggest that’s the
 problem. It took me a while to realize what exactly the problem was.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12529#comment:5>
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