[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 (Type    |              Version:  8.2.1
  checker)                           |             Keywords:
      Resolution:                    |  PatternSynonyms
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #14288            |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by RyanGlScott):

 * keywords:   => PatternSynonyms
 * failure:  None/Unknown => Compile-time crash or panic
 * component:  Compiler => Compiler (Type checker)
 * related:   => #14288


Comment:

 Yes, `kk` should definitely scope over the pattern synonym body. In fact,
 the only reason that it doesn't currently is due to #14288 (that is,
 `ScopedTypeVariables` doesn't pick up variables from nested `forall`s). I
 suspect fixing #14288 would quite naturally lead to a solution to this bug
 as well.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14498#comment:2>
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