[GHC] #12401: GHC panic! Template variable unbound in rewrite rule

[GHC]

#12401: GHC panic! Template variable unbound in rewrite rule
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        Reporter:  vagarenko         |                Owner:
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Windows           |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  crash                              |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by vagarenko):

 If I provide type signature for `mirror`:

 {{{#!hs
 mirror :: (Storable (PixelBaseComponent a)) => Image a -> Int -> Image a
 }}}

 it compiles fine.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12401#comment:1>
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