Thank you very much for your input, I've filled in the bug report:

Best regards,

On Wed, Oct 26, 2022 at 6:55 PM Serhiy Storchaka <> wrote:
26.10.22 11:17, Piotr Waszkiewicz пише:
> Hi,
> I would like to ask your guidance as I'm entirely sure whether the problem I'm experiencing should be posted in CPython's repo as a bug issue.
> I've tried using newly released Python 3.11 interpreter in some of my projects and one of them failed to start with "RuntimeError: invalid SRE code" error.
> Looking into implementation of one of the dependencies I've found out that the issue has been found out by a maintainer and fixed (
> It looks like this particular regexp caused the `re.compile()` method to raise:
> ```
>     re.compile(
>          r"(?P<h>^([01][0-9]|2[0-3]))"
>          r"((?P<m>([0-5][0-9]))?"
>          r"(?(5)(?P<s>([0-5][0-9]|60))?)"
>          r"(?(7)(\.(?P<ms>([0-9]{1,6})?))?))$"
>      )
> ```
> I've checked and this hasn't been an issue in all previous Python interpreter versions, starting from 3.6 (the oldest I've checked).
> What's more the regex i correctly recognized and does not cause any issues in other regexp implementations, e.g. the online tool
> Could somebody help me decide whether this is indeed a bug?

Yes, it is a bug, and I have found its cause. Please open an issue on
the CPython bug tracker.

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