aiohttp cannot be used in python 3.14.

[AraHaan]

Describe the bug

This is because they have already removed typing.ByteString that is used inside of payload.py.

They suggest either replacing it with bytes | bytearray or collections.abc.Buffer. For use as an ABC, prefer Sequence or collections.abc.Buffer.

To Reproduce

Clone the CPython main branch and build, then install pip and aiohttp.

Next try to run some code that depends on the latest version of aiohttp.

Expected behavior

Everything to work as aiohttp would be prepared for the removal of typing.ByteString. Preparing it now before it becomes stable is a good idea as then it requires less work later.

Logs/tracebacks

Traceback (most recent call last):
  File "<frozen runpy>", line 189, in _run_module_as_main
  File "<frozen runpy>", line 148, in _get_module_details
  File "<frozen runpy>", line 112, in _get_module_details
  File "__init__.py", line 8, in <module>
  File "__init__.py", line 23, in <module>
  File "client.py", line 49, in <module>
  File "__init__.py", line 6, in <module>
  File "client.py", line 38, in <module>
  File "payload.py", line 10, in <module>
ImportError: cannot import name 'ByteString' from 'typing' (C:\Users\User\OneDrive\Desktop\DiscordBot\pcbuild\bin\lib.zip\typing.pyc)

### Python Version

```console
$ python --version
3.14.0a0

aiohttp Version

$ python -m pip show aiohttp
3.9.5

multidict Version

$ python -m pip show multidict
6.0.5

yarl Version

$ python -m pip show yarl
1.9.4

OS

Windows

Related component

Server, Client

Additional context

No response

Code of Conduct

• I agree to follow the aio-libs Code of Conduct

[AraHaan]

Seems the change already happened, but waiting for a new release so I can get those changes.

#8408

Would be cool if aiohttp could do github only wheels on every non-stable commit until an official next release is made on pypi.

[webknjaz]

Alright, so we don't need to track it, then.

[Dreamsorcerer]

More to the point, if you are running CPython from source, you can do the same with aiohttp, just checkout the 3.10 branch.

[AraHaan]

I tried the 3.10 branch however the build fails, even when I manually invoke cython prior to setup.py bdist_wheel with the 3.14 self-built interpreter (it fails to copy the vendor include files and then properly allow them to be included..

And yes I am trying to build it on Windows with no clear building.md file that gives step by step instructions on how to properly build successfully.