[GHC] #14541: Stg lint failure while building ghc-stage2: compiler/stage2/build/Hoopl/Block.o

[GHC]

#14541: Stg lint failure while building ghc-stage2:
compiler/stage2/build/Hoopl/Block.o
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        Reporter:  duog              |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.3
      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 duog):

 It seems that `dataConRepArity` is returning 2 for Just0. Shouldn't one of
 those be being discarded as an "existential dictionary"?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14541#comment:1>
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