[GHC] #9160: Panic: Template variable unbound in rewrite rule

[GHC]

#9160: Panic: Template variable unbound in rewrite rule
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        Reporter:  mietek            |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:  7.8.3
       Component:  Compiler          |                 Version:  7.8.2
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  crash                              |               Test Case:
      Blocked By:                    |  indexed_types/should_fail/T9160
 Related Tickets:  #4524             |                Blocking:
                                     |  Differential Revisions:
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Comment (by George):

 I am also see this on ghc 7.10.1, not sure if this is another instance of
 this bug:

 cabal install bitmap
 [ 3 of 10] Compiling Data.Bitmap.IO   ( Data/Bitmap/IO.hs,
 dist/build/Data/Bitmap/IO.o )

 Data/Bitmap/IO.hs:1248:1: Warning:
     SPECIALISE pragma for non-overloaded function ‘myPlusPtr’

 Data/Bitmap/IO.hs:1249:1: Warning:
     SPECIALISE pragma for non-overloaded function ‘myPlusPtr’
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.10.1 for x86_64-apple-darwin):
         Template variable unbound in rewrite rule
   $fPixelComponentFloat3_X2Rc
   [$fPixelComponentFloat3_X2Rc]
   [$fPixelComponentFloat3_X2Rc]
   []
   []

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

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9160#comment:13>
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