[jhc] Can't build 0.7.8

[wren ng thornton]

Hello,

I just tried building 0.7.8 today and got this error:

src/Util/ContextMonad.hs:15:9:
     Overlapping instances for Error [String]
       arising from the superclasses of an instance declaration
                    at src/Util/ContextMonad.hs:15:9-45
     Matching instances:
       instance (transformers-0.2.1.0:Control.Monad.Trans.Error.ErrorList
                   a) =>
                Error [a]
         -- Defined in transformers-0.2.1.0:Control.Monad.Trans.Error
       instance [overlap ok] Error [String]
         -- Defined at src/Util/ContextMonad.hs:10:9-22
     In the instance declaration for `ContextMonad
                                        String (Either [String])'

Let me know if you need any more info.

-- 
Live well,
~wren