[GHC] #11821: Internal error: not in scope during type checking, but it passed the renamer

[GHC]

#11821: Internal error: not in scope during type checking, but it passed the
renamer
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        Reporter:  darchon           |                Owner:
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.0.2
       Component:  Compiler          |              Version:  8.0.1-rc3
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2146
       Wiki Page:                    |
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Comment (by Richard Eisenberg <eir@…>):

 In [changeset:"c5919f75afab9dd6f0a4a2670402024cece5da57/ghc"
 c5919f75/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="c5919f75afab9dd6f0a4a2670402024cece5da57"
 Remove the incredibly hairy splitTelescopeTvs.

 This patch removes splitTelescopeTvs by adding information about
 scoped type variables to TcTyCon. Vast simplification!

 This also fixes #11821 by bringing only unzonked vars into scope.

 Test case: polykinds/T11821
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11821#comment:8>
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