Hi!

While rebuilding the python related packages against the Python 3.15rc1
version we found that ipykernel fails to build from source [1].

Warnings are configured to be treated as errors during the tests and
Python 3.15 produces a new warning when using threads and fork. I added
a patch the ignores the new warning during the tests

I applied the fix in the sandbox [2] to be able to build the packages
that depend on ipykernel, please consider applying the patch to support
the upcoming 3.15 version.

Happy hacking,

[1]: https://debusine.debian.net/debian/r-python-python3.15/artifact/4495657/
[2]: https://debusine.debian.net/debian/r-python-python3.15/