Re: [Haskell-cafe] Problem with class Control.Monad.Error noMsg usage

On Tue, Dec 21, 2010 at 03:28:22PM +0000, Aaron Gray wrote:

I have been trying to build the Scheme in 24 Hours on WikiBooks :-

http://en.wikibooks.org/wiki/Write_Yourself_a_Scheme_in_48_Hours

http://jonathan.tang.name/files/scheme_in_48/code/listing10.hs

But I am getting an error :-

scheme.hs:289:6: `noMsg' is not a (visible) method of class `Error'

scheme.hs:290:6: `strMsg' is not a (visible) method of class `Error'

I don't get that here. Perhaps you're using an old version of monads-fd (0.1.0.0). I'd recommend installing mtl-2.0.1.0 instead.