overlapping instances in ghc-6.5

[Christian Maeder]

The attached 4 files compile with ghc-6.4.1 and fail with
ghc-6.5.20060201 (see below).

Also, if I delete the Int and Integer instances in 
Common/ATerm/Conversion.hs the error remains the same for ghc-6.5 
whereas ghc-6.4.1 correctly complains about
     "No instance for (ShATermConvertible Int)
       arising from use of `fromShATerm'' at
                 Common/ATerm/ConvInstances.hs:39:25-36"

(Common.Lib.Graph is basically the same as Data.Graph.Inductive.Tree)

Cheers Christian

ghc --make -no-recomp -fglasgow-exts -fallow-overlapping-instances 
Common/ATerm/ConvInstances.hs
Chasing modules from: Common/ATerm/ConvInstances.hs
[1 of 4] Compiling Common.ATerm.AbstractSyntax ( 
Common/ATerm/AbstractSyntax.hs, Common/ATerm/AbstractSyntax.o )
[2 of 4] Compiling Common.ATerm.Conversion ( Common/ATerm/Conversion.hs, 
Common/ATerm/Conversion.o )
[3 of 4] Compiling Common.Lib.Graph ( Common/Lib/Graph.hs, 
Common/Lib/Graph.o )
[4 of 4] Compiling Common.ATerm.ConvInstances ( 
Common/ATerm/ConvInstances.hs, Common/ATerm/ConvInstances.o )

Common/ATerm/ConvInstances.hs:31:0:
     Overlapping instances for Typeable (Common.Lib.Graph.Gr a b)
       arising from the superclasses of an instance declaration at 
Common/ATerm/ConvInstances.hs:31:0
     Matching instances:
       instance (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:26:0
     In the instance declaration for `ShATermConvertible 
(Common.Lib.Graph.Gr a
 
       b)'
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Common.tgz
Type: application/x-gtar
Size: 4302 bytes
Desc: not available
Url : http://www.haskell.org/pipermail/glasgow-haskell-bugs/attachments/20060206/cf6ee65f/Common.gtar