SPECIALIZE causing duplicate assembler symbols

The program below causes duplicate assembler symbols when compiled -O with ghc 6.9.20080816 (but not with ghc 6.8.2)

There's no profiling involved otherwise I'd have assumed this was a duplicate of #2410 (closed).

{-# LANGUAGE GADTs #-}
module Types where

data Prod a b = Prod a b

data Nil = Nil

class ProdSel f where
   nil :: f Nil
   prod :: f x -> f y -> f (Prod x y)

instance ProdSel SqlFields where
   nil = SFNil
   prod = SFProd

{-# SPECIALIZE reproject :: SqlFields a -> SqlFields a #-}

reproject :: ProdSel f => SqlFields a -> f a
reproject SFNil = nil
reproject (SFProd a b) = prod (reproject a) (reproject b)

data SqlFields a where
  SFNil :: SqlFields Nil
  SFProd :: SqlFields a -> SqlFields b -> SqlFields (Prod a b)

Trac metadata

Trac field	Value
Version	6.9
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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