[GHC] #9803: Poor error message for unbound variable in pattern synonym

[GHC]

#9803: Poor error message for unbound variable in pattern synonym
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        Reporter:  goldfire          |                Owner:  mpickering
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  7.9
  checker)                           |             Keywords:
      Resolution:                    |  PatternSynonyms
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 simonpj):

 OK Matthew, you're all set to look at this.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9803#comment:4>
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