Bump multimethod to 2.1 => crash under 3.14 with dataclasses-json

[bernhard-42]

There is an issue under Python 3.14 with multimethod==1.12 and dataclass-json as used e.g. by pygltflib

from collections.abc import Sequence
from dataclasses import dataclass

from dataclasses_json import dataclass_json
from multimethod import multimethod

@multimethod
def f(xs: Sequence[int]) -> int:
    return len(xs)

@dataclass_json
@dataclass
class Model:
    rows: list[int] | None = None

m = Model.from_json('{"rows": [1, 2]}')

• throws TypeError with multimethod==1.12 under Python 3.14
• succeeds with multimethod==2.1 under Python 3.14
• succeeds under Python 3.11-3.13 (this is what I tested) with multimethod==1.12 or multimethod==2.1

The trigger seems to be using multimethod with a parameterised abstract collection annotation.

The good thing is that multimethod==2.1 already fixed it.

Hence, I tried an editable cadquery 2.9.0.dev0 installation in a uvenv with multimethod==2.1 under Python 3.13 and Python 3.14

I also tried it

• with Python 3.11 (pypi) => success
• with an editable cadquery 2.9.0.dev0 anaconda installation for Python 3.14 with multimethod=2.1 (using environment.yml, omitting the custom black so that it it installs) => success

It seems to work well, so could you please bump multimethod>=2.1,<3.0.

[bernhard-42]

Thank you!

[bernhard-42]

@adam-urbanczyk Just ran into the same error and realized that setup.py didn't get the multimethod 2.1 change