Conal Elliott conal@microsoft.com writes:

In Zeep.hs:

module Zeep where instance Eq [(Int, Int)]

In tst.hs:

import Zeep import IOExts

The result:

....

ERROR "c:\hugs98/lib\Array.hs":60 - Cannot justify constraints in instance member binding *** Expression : (==) *** Type : Eq (Array a b) => Array a b -> Array a b ->Bool *** Given context : Eq (Array a b) *** Constraints : Eq [(a,b)]

Not really a bug, see Jeff's response (&cure) to a very similar bug report: http://haskell.org/pipermail/hugs-bugs/2001-December/000545.html --sigbjorn