Fatal Python error: deallocating None

[George Sakkis]

It's the first time in the three years I've been using python that a
program crashes without a nice traceback to give me a clue of what
might be wrong. After searching a little, it seems it's one of those
hard to get down to cases, so I've no idea where to look for. Briefly
what I do is, select some rows from one table, do some number crunching
and insert or update rows in another table. The C extensions I'm using
are numarray and MySQLdb (indirectly, through Sqlalchemy).

What makes the problem worse is that it's not deterministic; I can
restart it from (a little before) the point of crash and it doesn't
happen again at the same point, but it might happen further down. Now,
I wouldn't mind restarting it manually every time since the crashes are
not all that frequent; problem is, it's supposed to be a long-running
process that will probably take days to finish normally, so I want it
to run overnight too. Any hints ?

Thanks,
George