[issue36829] CLI option to make PyErr_WriteUnraisable abort the current process

[Thomas Grainger]

Thomas Grainger <tagrain at gmail.com> added the comment:

The point for me is that CI will fail if it happens, then I can use gdb to
find out the cause

On Thu, 9 May 2019, 23:17 STINNER Victor, <report at bugs.python.org> wrote:

>
> STINNER Victor <vstinner at redhat.com> added the comment:
>
> Ok, let me come back to the initial issue:
>
> Thomas Grainger:
> > Currently it's quite easy for these errors to go unnoticed. I'd like a
> way to easily detect these in CI. nedbat suggested piping the process
> output to another tool, and looking for 'Exception ignored in:' but this
> seems a little diff
>
> When PyErr_WriteUnraisable() is called before Python finalization, my PR
> 13187 allows to handle these exceptions: log them in a dedicated file,
> abort the process, maybe even open a network connection, etc. The hook
> allows to implement your chosen behavior.
>
> The problem is more during Python finalization: see attached
> too_late_unraisable.py example and my previous comment. If
> PyErr_WriteUnraisable() is called after sys.stderr is closed or closed to
> None, the function does nothing: the exception is not logged.
>
> The question now becomes: do *all* calls to PyErr_WriteUnraisable() must
> abort the process? What is the point? Only a very low level debugger like
> gdb can be used to see the exception.
>
> @Thomas Grainger: Do you want to have to use gdb to trace such very level
> exception?
>
> IMHO sadly when PyErr_WriteUnraisable() is called way too late, we should
> simply ignore such exceptions. And so my PR 13187 is good enough to cover
> most cases.
>
> If someone cares about exceptions raised very late during Python
> finalization, Python finalization should be enhanced. But this code is very
> fragile and is not deterministic. It is a work in progress for years to
> enhance it.
>
> ----------
>
> _______________________________________
> Python tracker <report at bugs.python.org>
> <https://bugs.python.org/issue36829>
> _______________________________________
>

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue36829>
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