[GHC] #14555: GHC Panic with TypeInType / levity polymorphism

[GHC]

#14555: GHC Panic with TypeInType / levity polymorphism
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        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.3
      Resolution:                    |             Keywords:
                                     |  LevityPolymorphism, TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #14563            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"8361b2c5a9f7a00f0024f44a43b851998ae41e33/ghc"
 8361b2c5/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="8361b2c5a9f7a00f0024f44a43b851998ae41e33"
 Fix SigTvs at the kind level

 This patch fixes two bugs in the treatment of SigTvs at the
 kind level:

 - We should always generalise them, never default them
   (Trac #14555, #14563)

 - We should check if they get unified with each other
   (Trac #11203)

 Both are described in TcHsType
    Note [Kind generalisation and SigTvs]
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14555#comment:3>
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