[GHC] #7003: 'impossible' compile time error, when using `runStream'.

[GHC]

#7003: 'impossible' compile time error, when using `runStream'.
-------------------------+--------------------------------------------------
    Reporter:  dbanas    |       Owner:                    
        Type:  bug       |      Status:  new               
    Priority:  normal    |   Milestone:                    
   Component:  Compiler  |     Version:  7.4.2             
    Keywords:            |          Os:  Linux             
Architecture:  x86       |     Failure:  Compile-time crash
  Difficulty:  Unknown   |    Testcase:                    
   Blockedby:            |    Blocking:                    
     Related:            |  
-------------------------+--------------------------------------------------
Changes (by simonpj):

  * difficulty:  => Unknown


Old description:

> ghc: panic! (the 'impossible' happened)
>   (GHC version 7.0.3 for i386-unknown-linux):
>         addTickHsExpr
>     (|/\(@ a{tv aZE} [sk]).
>       (arrows-0.4.4.0:Control.Arrow.Transformer.Stream.runStream{v rfV}
> [gid])
>       @ t{tv aZY} [sk]
>       @ a{tv aZE} [sk]
>       @ t{tv a102} [sk]
>       @ t{tv aZZ} [sk]
>         $dArrowLoop{v aZF} [lid]
>         ((\ ((x{v aZc} [lid] :: t{tv a102} [sk]))
>             -> {49:30-52}
>                ((base:Control.Arrow.loop{v 020} [gid[ClassOp]])
>                 @
> (arrows-0.4.4.0:Control.Arrow.Transformer.Stream.StreamArrow{tc rgp}
>                      t{tv aZY} [sk])
>                   $dArrowLoop{v aZG} [lid])
>                @ (t{tv a101} [sk], t{tv a102} [sk])
>                @ d{tv a100} [sk]
>                @ t{tv aZZ} [sk]
>                  (((base:Control.Arrow.arr{v 01V} [gid[ClassOp]])
>                    @
> (arrows-0.4.4.0:Control.Arrow.Transformer.Stream.StreamArrow{tc rgp}
>                         t{tv aZY} [sk])
>                      $dArrow{v aZI} [lid])
>                   @ ((t{tv a101} [sk], t{tv a102} [sk]), d{tv a100} [sk])
>                   @ (t{tv aZZ} [sk], d{tv a100} [sk])
>                     k{v aZ9} [lid]) -< (s0{v aZa} [lid], x{v aZc}
> [lid])))|)
>
> Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

New description:

 {{{
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.0.3 for i386-unknown-linux):
         addTickHsExpr
     (|/\(@ a{tv aZE} [sk]).
       (arrows-0.4.4.0:Control.Arrow.Transformer.Stream.runStream{v rfV}
 [gid])
       @ t{tv aZY} [sk]
       @ a{tv aZE} [sk]
       @ t{tv a102} [sk]
       @ t{tv aZZ} [sk]
         $dArrowLoop{v aZF} [lid]
         ((\ ((x{v aZc} [lid] :: t{tv a102} [sk]))
             -> {49:30-52}
                ((base:Control.Arrow.loop{v 020} [gid[ClassOp]])
                 @
 (arrows-0.4.4.0:Control.Arrow.Transformer.Stream.StreamArrow{tc rgp}
                      t{tv aZY} [sk])
                   $dArrowLoop{v aZG} [lid])
                @ (t{tv a101} [sk], t{tv a102} [sk])
                @ d{tv a100} [sk]
                @ t{tv aZZ} [sk]
                  (((base:Control.Arrow.arr{v 01V} [gid[ClassOp]])
                    @
 (arrows-0.4.4.0:Control.Arrow.Transformer.Stream.StreamArrow{tc rgp}
                         t{tv aZY} [sk])
                      $dArrow{v aZI} [lid])
                   @ ((t{tv a101} [sk], t{tv a102} [sk]), d{tv a100} [sk])
                   @ (t{tv aZZ} [sk], d{tv a100} [sk])
                     k{v aZ9} [lid]) -< (s0{v aZa} [lid], x{v aZc}
 [lid])))|)

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

--

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7003#comment:2>
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