bug report

Hello.

I am reporting a bug in the GHCi Haskell interpreter as requested by 
the program itself. GHC is 5.04.2 running on SunOS 5.8.

The interpreter encountered a panic condition when trying to load a
parser produced by Happy the parser generator.

The commands I am using are as follows:

----------------------------------------------------------------------
% happy -gac -i Parser.y 
shift/reduce conflicts:  6
% ghci Parser.hs         
   ___         ___ _
  / _ \ /\  /\/ __(_)
 / /_\// /_/ / /  | |      GHC Interactive, version 5.04.2, for Haskell 98.
/ /_\\/ __  / /___| |      http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|      Type :? for help.

Loading package base ... linking ... done.
Loading package haskell98 ... linking ... done.
Compiling MonadLexer       ( MonadLexer.hs, interpreted )
Compiling Parser           ( Parser.hs, interpreted )
WARNING: ignoring polymorphic case in interpreted mode.
   Possibly due to strict polymorphic/functional constructor args.
   Your program may leak space unexpectedly.

ghc-5.04.2: panic! (the `impossible' happened, GHC version 5.04.2):
        ByteCodeGen.pushAtom.pushStr

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


> 
----------------------------------------------------------------------

When I try to produce the parser without GHC extensions, I get the 
following result:

----------------------------------------------------------------------
% happy  -i Parser.y  
shift/reduce conflicts:  6
% ghci Parser.hs     
   ___         ___ _
  / _ \ /\  /\/ __(_)
 / /_\// /_/ / /  | |      GHC Interactive, version 5.04.2, for Haskell 98.
/ /_\\/ __  / /___| |      http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|      Type :? for help.

Loading package base ... linking ... done.
Loading package haskell98 ... linking ... done.
Compiling MonadLexer       ( MonadLexer.hs, interpreted )
Compiling Parser           ( Parser.hs, interpreted )
WARNING: ignoring polymorphic case in interpreted mode.
   Possibly due to strict polymorphic/functional constructor args.
   Your program may leak space unexpectedly.


During interactive linking, GHCi couldn't find the following symbol:
  DataziTuple_Z92T_con_info or DataziTuple_Z92T_static_info
This may be due to you not asking GHCi to load extra object files,
archives or DLLs needed by your current session.  Restart GHCi, specifying
the missing library using the -L/path/to/object/dir and -lmissinglibname
flags, or simply by naming the relevant files on the GHCi command line.
Alternatively, this link failure might indicate a bug in GHCi.
If you suspect the latter, please send a bug report to:
  glasgow-haskell-bugs@xxxxxxxxxxx
----------------------------------------------------------------------

The Hugs interpreter seems to run the parser fine. Also, 
non-interactive compilation, i.e. "ghc -c Parser.hs" runs without 
complaints.


Juhana Helovuo
Tampere University of Technology