On Sun, Jun 22, 2008 at 8:07 AM, Antoine Pitrou <report@bugs.python.org> wrote:
> You mean they should be detected when the exception is set? I was afraid
> that it may make exception raising slower. Reporting is not performance
> sensitive in comparison to exception raising.
>
> (the "problem mentioned here" is already avoided in the patch, but the
> detection of other cycles is deferred to exception reporting for the
> reason given above)

I meant only that trivial cycles should be detected.  However, I
hadn't read your patch, so I didn't realize you already knew of a way
to create a non-trivial cycle.

This has placed a niggling doubt in my mind about chaining the
exceptions, rather than the tracebacks.  Hrm.

>> * PyErr_Display is used by PyErr_Print, and it must end up with no
>> active exception.  Additionally, third party code may depend on this
>> semantic.  Maybe PyErr_DisplayEx?
>
> I was not proposing to change the exception swallowing semantics, just
> to add a return value indicating if any errors had occurred while
> displaying the exception.

Ahh, harmless then, but to what benefit?  Wouldn't the traceback
module be better suited to any possible error reporting?