[GHC] #14498: GHC internal error: "not in scope during TC but it passed the renamer"

[GHC]

#14498: GHC internal error: "not in scope during TC but it passed the renamer"
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        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      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 simonpj):

 Hmm.  It's clear that `t` and `k'` from the pattern signature should scope
 over the pattern declaration, by the usual rules (top level forall'd
 variables from the signature do scope in this way).  But what about the
 existentials, `a` and `kk`?

 I think it would make sense for them to scope too, in the same way.  Does
 everyone agree?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14498#comment:1>
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