overlapping instances in ghc-6.5

Christian Maeder maeder at tzi.de
Fri Feb 3 10:46:28 EST 2006


with 6.5.20060201 I get now an error for some overlapping instances that 
were ok for ghc-6.4.1. Did some options change?

I use:

-fglasgow-exts -fno-monomorphism-restriction \
     -fallow-overlapping-instances -fallow-undecidable-instances


     Overlapping instances for Typeable (Common.Lib.Graph.Gr a b)
       arising from the superclasses of an instance declaration at 
     Matching instances:
       instance (Data.Typeable.Typeable1 s, Typeable a) => Typeable (s a)
         -- Imported from Data.Typeable
       instance [overlap ok] (Typeable a, Typeable b) =>
                             Typeable (Common.Lib.Graph.Gr a b)
         -- Defined at Common/ATerm/ConvInstances.hs:34:0
     In the instance declaration for `ShATermConvertible 
(Common.Lib.Graph.Gr a b)'

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