Template haskell bug 1

Windows XP

D:\Tools\ghc>ghc-6.2.1\bin\ghc.exe -fglasgow-exts foo.hs
ghc.exe: panic! (the `impossible' happened, GHC version 6.2.1):
        deSugar/DsMeta.hs:286: Non-exhaustive patterns in function repC



module Foo where

import Language.Haskell.THSyntax

class MyInterface a where
        foo :: a -> Int

data AnyMyInterface = forall a. (MyInterface a) => AnyMyInterface a

test =
    do{
        d <- unQ(reifyDecl AnyMyInterface)
      ; print d
      }