[GHC] #7975: "impossible" failure while type checking

[GHC]

#7975: "impossible" failure while type checking
-------------------------------+--------------------------------------------
Reporter:  jonnadal            |          Owner:                         
    Type:  bug                 |         Status:  new                    
Priority:  normal              |      Component:  Compiler (Type checker)
 Version:  7.6.3               |       Keywords:                         
      Os:  MacOS X             |   Architecture:  x86                    
 Failure:  Compile-time crash  |      Blockedby:                         
Blocking:                      |        Related:                         
-------------------------------+--------------------------------------------
 $ cat failure.hs
 {{{
 import Control.Monad.Trans.Class
 oops :: () -> IO () -> IO ()
 oops = lift . lift
 main = return ()
 }}}

 $ ghc failure.hs
 {{{
 [1 of 1] Compiling Main             ( failure.hs, failure.o )

 failure.hs:3:8:ghc: panic! (the 'impossible' happened)
   (GHC version 7.6.3 for i386-apple-darwin):
         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/7975>
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