[GHC] #7368: kindFunResult panic in the

[GHC]

#7368: kindFunResult panic in the
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    Reporter:  ChrisN                   |       Owner:                             
        Type:  bug                      |      Status:  new                        
    Priority:  normal                   |   Milestone:                             
   Component:  Compiler (Type checker)  |     Version:  7.6.1                      
    Keywords:  Kinds, kindfunresult     |          Os:  Unknown/Multiple           
Architecture:  Unknown/Multiple         |     Failure:  Compile-time crash         
  Difficulty:  Unknown                  |    Testcase:  typecheck/should_fail/T7368
   Blockedby:                           |    Blocking:                             
     Related:                           |  
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Comment(by arkeet):

 I don't know if this should be a separate bug, but the following (ill-
 typed) code produces the same error, both on 7.6.1 and on HEAD:

 {{{
 {-# LANGUAGE Rank2Types #-}
 newtype Bad f = Bad (forall a. (f a -> a))
 fun :: f (Bad f) -> Bad f
 fun (Bad x) = Bad x
 }}}

 {{{
 [1 of 1] Compiling Main             ( bad.hs, bad.o )
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.7.20121127 for x86_64-unknown-linux):
         kindFunResult ghc-prim:GHC.Prim.*{(w) tc 34d}

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7368#comment:5>
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