Hi!

While rebuilding the python related packages against the Python 3.15rc2
version we found that python-txi2p-tahoe fails to build from source [1].

The error is:

TypeError: ParserProtocol.__init__() takes 5 positional arguments but 6 were given

This happens because functools.partial is now an object, and the way the
code is used causes Python to add a `self` parameter that shouldn't be
there.

I've prepared a patch that drops the use of functools.partial, it wasn't
actually needed. This patch should probably be forwarded upstream.

I've applied the fix in the sandbox [2] to verify that it builds
successfully, please consider applying the patch to support the upcoming
3.15 version.

Setting the severity to important for now. Once Python 3.15 is released,
it will be added to python3-defaults and this bug will become release
critical.

Happy hacking,

[1]: https://debusine.debian.net/debian/r-python-python3.15/artifact/4455091/
[2]: https://debusine.debian.net/debian/r-python-python3.15/