[Haskell-beginners] Re: Debugging overlapping instances (mtl vs transformers)

On 09/09/2010 10:35, Paolo Losi wrote:

Overlapping instances for Monad (Either String) arising from a use of `tstampToForecasts' at ThreeLab/Gfs.hs:94:32-55 Matching instances: instance (Control.Monad.Trans.Error.Error e) => Monad (Either e) -- Defined in Control.Monad.Trans.Error instance Monad (Either e) -- Defined in mtl-1.1.1.0:Control.Monad.Error

Forgot to say... that's the error I get using cabal build