pytorch cannot be installed from cpu index when opencv is also a dependency

[Dronakurl]

Summary

When following the instructions on using uv with pytorch on the astral website, I encounter an error when adding opencv.

I get the error

3.807 error: Distribution `torch==2.6.0 @ registry+https://download.pytorch.org/whl/cpu` can't be installed because it doesn't have a source distribution or wheel for the current platform
3.807
3.807 hint: You're on Linux (`manylinux_2_36_x86_64`), but `torch` (v2.6.0) only has wheels for the following platform: `macosx_11_0_arm64`

Here is the Dockerfile with minimal example that produces this error. Without opencv-python, it works, so torch is installed.
I read #11406, but could not find anything that helps me with that.

FROM ghcr.io/astral-sh/uv:0.5.24-debian-slim

COPY <<EOF /mre/pyproject.toml
[project]
name = "project"
version = "0.1.0"
requires-python = "==3.12.0"
dependencies = [
  "torch>1.13.1'",
  "torchvision>=0.14.1",
  "opencv-python",
]

[tool.uv.sources]
torch = [{ index = "pytorch-cpu" }]
torchvision = [{ index = "pytorch-cpu" }]

[[tool.uv.index]]
name = "pytorch-cpu"
url = "https://download.pytorch.org/whl/cpu"
explicit = true
EOF

WORKDIR /mre
RUN uv  sync -U 

Run with
docker build -t uvdebug . --progress plain --no-cache

Platform

Ubuntu 24.04, x86_64

Version

uv 0.6.0

Python version

Python 3.12.3

[charliermarsh]

I fixed this on main in #11546.

[Dronakurl]

Thank you very much! I missed the other issue in my search.

[charliermarsh]

No worries, it's not at all obvious that it's the same issue, I just learned when debugging that it was also triggered by OpenCV in the end.