Support for Python 3.14 on ubuntu

[jonathan343]

Overview

Hey team, sorry if this is a duplicate but I didn't see any other related issue.

Per PEP 0745, Python 3.14 is scheduled to release next month on 2025-10-07. I noticed our repo's CI failing when trying to run on 3.14-dev and discovered it was due to not being able to install aiohttp on ubuntu when using Python 3.14.

Is there ongoing work or a timeline for getting this issue resolved? Would appreciate any update here, thank you!

Reproduction Steps

Try to install aiohttp using Python 3.14 on an ubuntu machine:

ubuntu@ip-172-31-28-218:~$ uv venv -p 3.14
Using CPython 3.14.0rc2 interpreter at: .local/bin/python3.14
Creating virtual environment at: .venv
Activate with: source .venv/bin/activate
ubuntu@ip-172-31-28-218:~$ . .venv/bin/activate
(ubuntu) ubuntu@ip-172-31-28-218:~$ uv pip install aiohttp
Resolved 9 packages in 132ms
  × Failed to build `aiohttp==3.12.15`
  ├─▶ The build backend returned an error
  ╰─▶ Call to `setuptools.build_meta.build_wheel` failed (exit status: 1)

      [stdout]
      running bdist_wheel
      running build
      running build_py
      copying aiohttp/client_middlewares.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/http_exceptions.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/typedefs.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/__init__.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/multipart.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/worker.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/streams.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_middlewares.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/http_websocket.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/base_protocol.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_app.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/resolver.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/cookiejar.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_urldispatcher.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/client_exceptions.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/payload.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/abc.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/_cookie_helpers.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_routedef.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_server.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_protocol.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/formdata.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/hdrs.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_request.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/client_proto.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/tracing.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/tcp_helpers.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_fileresponse.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/http.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/pytest_plugin.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/http_parser.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/compression_utils.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/client_middleware_digest_auth.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/log.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_runner.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_log.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/test_utils.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/client_ws.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_exceptions.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/payload_streamer.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/client.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/helpers.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_response.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/http_writer.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/web_ws.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/connector.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/client_reqrep.py -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/_websocket/__init__.py -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      copying aiohttp/_websocket/models.py -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      copying aiohttp/_websocket/reader_c.py -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      copying aiohttp/_websocket/helpers.py -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      copying aiohttp/_websocket/writer.py -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      copying aiohttp/_websocket/reader.py -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      copying aiohttp/_websocket/reader_py.py -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      running egg_info
      writing aiohttp.egg-info/PKG-INFO
      writing dependency_links to aiohttp.egg-info/dependency_links.txt
      writing requirements to aiohttp.egg-info/requires.txt
      writing top-level names to aiohttp.egg-info/top_level.txt
      reading manifest file 'aiohttp.egg-info/SOURCES.txt'
      reading manifest template 'MANIFEST.in'
      adding license file 'LICENSE.txt'
      adding license file 'vendor/llhttp/LICENSE'
      writing manifest file 'aiohttp.egg-info/SOURCES.txt'
      copying aiohttp/_cparser.pxd -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/_find_header.pxd -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/_headers.pxi -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/_http_parser.pyx -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/_http_writer.pyx -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/py.typed -> build/lib.linux-x86_64-cpython-314/aiohttp
      copying aiohttp/.hash/_cparser.pxd.hash -> build/lib.linux-x86_64-cpython-314/aiohttp/.hash
      copying aiohttp/.hash/_find_header.pxd.hash -> build/lib.linux-x86_64-cpython-314/aiohttp/.hash
      copying aiohttp/.hash/_http_parser.pyx.hash -> build/lib.linux-x86_64-cpython-314/aiohttp/.hash
      copying aiohttp/.hash/_http_writer.pyx.hash -> build/lib.linux-x86_64-cpython-314/aiohttp/.hash
      copying aiohttp/.hash/hdrs.py.hash -> build/lib.linux-x86_64-cpython-314/aiohttp/.hash
      copying aiohttp/_websocket/mask.pxd -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      copying aiohttp/_websocket/mask.pyx -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      copying aiohttp/_websocket/reader_c.pxd -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket
      copying aiohttp/_websocket/.hash/mask.pxd.hash -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket/.hash
      copying aiohttp/_websocket/.hash/mask.pyx.hash -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket/.hash
      copying aiohttp/_websocket/.hash/reader_c.pxd.hash -> build/lib.linux-x86_64-cpython-314/aiohttp/_websocket/.hash
      running build_ext
      building 'aiohttp._websocket.mask' extension
      cc -pthread -fno-strict-overflow -Wsign-compare -Wunreachable-code -DNDEBUG -g -O3 -Wall -fPIC -fPIC -I/home/ubuntu/.cache/uv/builds-v0/.tmplRRJVM/include -I/home/ubuntu/.local/share/uv/python/cpython-3.14.0rc2-linux-x86_64-gnu/include/python3.14
      -c aiohttp/_websocket/mask.c -o build/temp.linux-x86_64-cpython-314/aiohttp/_websocket/mask.o

      [stderr]
      *********************
      * Accelerated build *
      *********************
      warning: no files found matching 'aiohttp' anywhere in distribution
      warning: no files found matching '*.pyi' anywhere in distribution
      warning: no previously-included files matching '*.pyc' found anywhere in distribution
      warning: no previously-included files matching '*.pyd' found anywhere in distribution
      warning: no previously-included files matching '*.so' found anywhere in distribution
      warning: no previously-included files matching '*.lib' found anywhere in distribution
      warning: no previously-included files matching '*.dll' found anywhere in distribution
      warning: no previously-included files matching '*.a' found anywhere in distribution
      warning: no previously-included files matching '*.obj' found anywhere in distribution
      warning: no previously-included files found matching 'aiohttp/*.html'
      no previously-included directories found matching 'docs/_build'
      error: command 'cc' failed: No such file or directory

      hint: This usually indicates a problem with the package or the build environment.

Describe the solution you'd like

Aiohttp to be installable using Python 3.14 on ubuntu.

Describe alternatives you've considered

N/A

Related component

Client

Additional context

No response

Code of Conduct

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

[Cycloctane]

That failing test should not affect installation. aiohttp currently does not provide binary wheels for python3.14. You should install a c compiler before installing aiohttp from sdist.

[jonathan343]

Thanks for your response.

This affects anyone trying to run CI for Python 3.14 on ubuntu and has a dependency on aiohttp. This is very common for package maintainers to try and catch issues early before the GA date.

You should install a c compiler before installing aiohttp from sdist.

We could probably do this temporarily for 3.14 only to work around the issue. Is there a rough timeline for getting 3.14 wheels?

[Dreamsorcerer]

If anyone would like to help, there is currently one failing test on 3.14 which appears to be caused by some change in equality comparison. We could do with someone figuring out exactly what changed in 3.14 and understanding if that's a regression or a deliberate change.

Other than that, I'm hoping the changes needed for free-threading support will be done and merged in shortly, which would be good to include alongside 3.14 support.

[Cycloctane]

I guess it is because the new partitioned attribute in python3.14 http.cookies. Legacy cookiejar pickles do not have this attribute, which makes equality assertion failed. It also makes cookiejars pickled in python3.14 incompatible with previous python versions.

[Dreamsorcerer]

Legacy cookiejar pickles do not have this attribute, which makes equality assertion failed.

Hmm, that could be it. Maybe we can copy the cookies after unpickling to get the default values or something?

[Dreamsorcerer]

We've added a 3.14 version in #11533, but now we seem to have another test failing to do with timing...

[Dreamsorcerer]

Hmm, one last problem seems to be on Windows only. For some reason, it looks like compression has changed, but only on Windows on 3.14:
https://github.com/aio-libs/aiohttp/actions/runs/17953438550/job/51144216029?pr=11533

[Dreamsorcerer]

On Windows, zlib-ng is now used as the implementation of the zlib module in the default binaries.

So, probably need to refactor that test in some way..