<<loop>> reading in external Core

There seems to be a bug in the latest version of GHC involving 
renaming/typechecking external Core files (well, besides the last 3 bugs
I posted about...):


$ ghc -fext-core -fno-code Hello.hs
/home/deforest/ghc6.1src/fptools/ghc/compiler/ghc-inplace -fext-core -fno-code 
Hello.hs
$ ghc Hello.hcr
/home/deforest/ghc6.1src/fptools/ghc/compiler/ghc-inplace Hello.hcr
ghc-6.1: panic! (the `impossible' happened, GHC version 6.1):
        <<loop>>

Please report it as a compiler bug to glasgow-haskell-bugs@xxxxxxxxxxx,
or http://sourceforge.net/projects/ghc/.

$ cat Hello.hs
cat Hello.hs
module Hello where

foo = putStrLn "Hello world!"
$ cat Hello.hcr
cat Hello.hcr
%module Hello
  foo1 :: GHCziIOBase.IO GHCziBase.Z0T =
    SystemziIO.putStrLn
    (GHCziBase.unpackCStringzh ("Hello world!"::GHCziPrim.Addrzh));
  Hello.foo :: GHCziIOBase.IO GHCziBase.Z0T = foo1;

I get the <<loop>> message with every .hcr file I've tried (restricting it
to ones that don't define a "main" function, due to the issue mentioned in
my previous post). This is with a GHC built from sources downloaded from 
CVS today. If I try to narrow things down by adding various verbosity options,
the error message gets printed right after the renamer stats get printed out;
that's as much as I've been able to figure out.
 
-- 
Kirsten Chevalier * krc@xxxxxxxxxxxxxxxxxxx * Often in error, never in doubt