tcrun032 regressed

The tcrun032 test:

{-# OPTIONS -fglasgow-exts -fallow-undecidable-instances #-}

-- This tests the recursive-dictionary stuff.
--
-- The derived instance needs 

module Main where

data Fix f = In (f (Fix f))  deriving( Show, Eq )
data L x = Nil | Cons Int x  deriving (Show, Eq)

main = do { print (In Nil);
        print (In Nil == In Nil) }

now fails with:

tcrun032.hs:9:5:
    No instance for (Show (f (Fix f)))
      arising from the 'deriving' clause of a data type declaration
      at tcrun032.hs:9:5
    Possible fix: add an instance declaration for (Show (f (Fix f)))
    When deriving the instance for `Show (Fix f)'

tcrun032.hs:9:5:
    No instance for (Eq (f (Fix f)))
      arising from the 'deriving' clause of a data type declaration
      at tcrun032.hs:9:5
    Possible fix: add an instance declaration for (Eq (f (Fix f)))
    When deriving the instance for `Eq (Fix f)'

in the 6.6 branch. Both 6.6 and the HEAD work.

Trac metadata

Trac field	Value
Version	6.6
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	Unknown
Architecture	Unknown