Windows 3.13.7 build regression ModuleNotFoundError: No module named '_posixsubprocess' #774
Description
We are happily using uv and the Python distributions shipped through this project in all of our CI.
Over at https://github.com/cda-tum/mqt-problemsolver we noticed a regression in the latest release that affects our CI. More specifically, it affects Python 3.13 on Windows.
-
Successful build a week ago downloading
cpython-3.13.6-windows-x86_64-none -
First failing build two days ago dowloading
cpython-3.13.7-windows-x86_64-none
The precise error is
path = 'D:\\a\\mqt-problemsolver\\mqt-problemsolver\\.nox\\tests-3-13\\Scripts\\python.exe'
args = ['D:\\a\\mqt-problemsolver\\mqt-problemsolver\\.nox\\tests-3-13\\Scripts\\python.exe', '-c', 'from multiprocessing.resource_tracker import main;main(15)']
passfds = [12, 15]
def spawnv_passfds(path, args, passfds):
> import _posixsubprocess
E ModuleNotFoundError: No module named '_posixsubprocess'
The same test suite runs perfectly fine on Ubuntu 24.04, macos-13, macos-14, as well as on Windows with Python 3.9-3.12.
How to reproduce:
git clone https://github.com/cda-tum/mqt-problemsolver
cd mqt-problemsolver
uv run --python 3.13.7 pytest
Changing to
uv run --python 3.13.6 pytest
makes the test pass.
Anything apparent to you that could be the cause for this?
Thanks for your help!