http://hackage.haskell.org/trac/ghc/ticket/4268  

--- haskell-vector-0.9.1.orig/Data/Vector/Fusion/Stream/Monadic.hs	2012-02-10 23:48:51.000000000 +0100
+++ haskell-vector-0.9.1/Data/Vector/Fusion/Stream/Monadic.hs	2012-02-10 23:49:04.000000000 +0100
@@ -94,15 +94,19 @@
 import Data.Word ( Word8, Word16, Word32, Word, Word64 )
 
 #if __GLASGOW_HASKELL__ >= 700
+#if 0
 import GHC.Exts ( SpecConstrAnnotation(..) )
 #endif
+#endif
 
 #include "vector.h"
 
 data SPEC = SPEC | SPEC2
 #if __GLASGOW_HASKELL__ >= 700
+#if 0
 {-# ANN type SPEC ForceSpecConstr #-}
 #endif
+#endif
 
 emptyStream :: String
 {-# NOINLINE emptyStream #-}