[Haskell-beginners] Builds with cabal, but not with GHC

Brent Yorgey byorgey at seas.upenn.edu
Wed Sep 28 17:37:14 CEST 2011

On Wed, Sep 28, 2011 at 03:03:33PM +0000, Amy de Buitléir wrote:
> Test.hs:20:9:
>     No instance for (mtl-
>                        CPError (ErrorT CPError IO))

I don't know a solution, but just want to point out that this error
message smacks of inconsistent package versions being used.  Something
else used mtl- and the current module is being compiled with a
different version of mtl, or something like that.  Hopefully this can
provide a fruitful direction of investigation...


More information about the Beginners mailing list