[Haskell-cafe] Mixing mtl- and transformers-using libraries

[Joachim Breitner]

Hi,

I have a rather large project here that uses standard mtl stuff. This
program now wants to use salvia, which in turn uses the transformers
library. The result is this:

X.hs:163:29:
    Overlapping instances for Monad (Either String)
      arising from a use of `neuePersonCommit' at X.hs:163:29-48
    Matching instances:
      instance (transformers-0.1.4.0:Control.Monad.Trans.Error.Error e) =>
               Monad (Either e)
        -- Defined in transformers-0.1.4.0:Control.Monad.Trans.Error
      instance (Control.Monad.Error.Class.Error e) => Monad (Either e)
        -- Defined in Control.Monad.Error

Is there any way of using salvia without having ghc consider instances
from transformers?

Thanks,
Joachim

-- 
Joachim "nomeata" Breitner
  mail: mail at joachim-breitner.de | ICQ# 74513189 | GPG-Key: 4743206C
  JID: nomeata at joachim-breitner.de | http://www.joachim-breitner.de/
  Debian Developer: nomeata at debian.org
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