Can't upload a newish package

[Bryan O'Sullivan]

I'm using ghc 6.8.2, and can't upload the LLVM bindings from
http://darcs.serpentine.com/llvm/

Here's the error I get from "cabal-upload -v":

  line 41: Parse of field 'extensions' failed:

Unfortunately, it includes no further details.

And here's the extensions section from the .cabal file:

  extensions:
      EmptyDataDecls
      FlexibleInstances
      ForeignFunctionInterface
      GeneralizedNewtypeDeriving
      TypeOperators
      TypeSynonymInstances