Bug in GHC 6.4.1 and 6.4.2

[Fritz Henglein]

According to a message from GHCi, version 6.4.1 (see below; bug also
reproduceable with 6.4.2, though not shown here since it consistently
resulted in a core dump without prior message) under Windows XP (fully
updated per 2006-07-15), I am herewith reporting what appears to be a
bug in GHC.  Please see transcript below; the source file in question
is included as an attachment.  (Lacking both efficient Haskell
programming skills and an understanding of the internals of GHC I have
refrained from attempting to isolate the bug by reducing the code.)
Should there be a simple work-around or something unsafe in my code
(though I wouldn't know what: no "unsafe" operations are used; no
polymorphism is present), I would greatly appreciate hearing about it.

Sincerely,
Fritz



:load "c:/henglein/Software/haskell/Basic.hs"
   ___         ___ _
  / _ \ /\  /\/ __(_)
 / /_\// /_/ / /  | |      GHC Interactive, version 6.4.1, for Haskell 98.
/ /_\\/ __  / /___| |      http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|      Type :? for help.

Loading package base-1.0 ... linking ... done.
Prelude> Compiling BasicDiscrimination (
c:/henglein/Software/haskell/Basic.hs, interpreted )
Ok, modules loaded: BasicDiscrimination.
*BasicDiscrimination> d <- mkDiscriminator
Loading package haskell98-1.0 ... linking ... done.
*BasicDiscrimination> res <- d [(5, "kdjfkd"), (8, "kjdkfjd")]
<interactive>: internal error: EVACUATED object entered!
    Please report this as a bug to glasgow-haskell-bugs at haskell.org,
    or http://www.sourceforge.net/projects/ghc/


-- 
Fritz Henglein, Ph.D.
Professor mso
Dept. of Computer Science, University of Copenhagen (DIKU)
Universitetsparken 1
DK-2100 Copenhagen
Denmark
Email: henglein at diku.dk
Tel.: +45-35321463 (office), +45-41414158 (cell)
Skype: henglein
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Basic.hs
Type: application/octet-stream
Size: 1668 bytes
Desc: not available
Url : http://www.haskell.org/pipermail/glasgow-haskell-bugs/attachments/20060716/2e8373cc/Basic.obj