Type checker hangs

The following program gets GHC stuck in Renamer/typechecker. This compiles correctly in 7.6.3.

{-# LANGUAGE DeriveDataTypeable #-}

module Type.Type where

import Data.Data
import qualified Data.UnionFind.IO as UF

data SrcSpan = Span String | NoSpan String
    deriving (Eq, Ord, Data, Typeable)

data Located e = L SrcSpan e
    deriving (Eq, Ord, Data, Typeable)

Removing either the:

import qualified Data.UnionFind.IO as UF

or

data Located e = L SrcSpan e
    deriving (Eq, Ord, Data, Typeable)

or

Removing the Eq Ord from Located:

data Located e = L SrcSpan e
    deriving (Data, Typeable)

will allow it to terminate.

ddump-tc-trace shows it is related to the derived typeable instance.

The log is attached.

I am compiling with:

arm-apple-darwin10-ghc -staticlib -ddump-tc-trace Type/Type.hs -v -threaded

I don't have a x86 build of HEAD handy, I think if someone could try this program in HEAD then we will know if it is ARM / GHC iOS / stage1 specific or not.

Trac metadata

Trac field	Value
Version	7.7
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	MacOS X
Architecture