Hi, Am Donnerstag, den 06.05.2010, 22:42 +1000 schrieb Ivan Lazar Miljenovic:

Joachim Breitner writes:

...

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?

Switch to using transformers yourself (I believe it's API compatible with mtl)?

I tried, but other dependencies still use mtl, still both instances are in scope. Greetings, Joachim -- Joachim "nomeata" Breitner Debian Developer nomeata@debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nomeata@joachim-breitner.de | http://people.debian.org/~nomeata