`[tool.uv.sources]` does not override transitive dependencies

[Avasam]

Summary

Using uv.sources to point a dependency to a local wheel file works. But not if that dependency is also another dep's dependency.

Example to replicate on Windows + Python 3.14:

pyproject.toml

dependencies = [
  "PyWinCtl >=0.0.42", # Has pywin32 as a dependency
  "pywin32 >=307; sys_platform == 'win32' and python_version < '3.14'", # Python 3.13 support
]
[tool.uv.sources]
# wheel taken from https://github.com/mhammond/pywin32/actions/runs/15353580238
pywin32 = { path = "./scripts/pywin32-310.1-cp314-cp314-win_amd64.whl", marker = "python_version >= '3.14'" } # Python 3.14 support

Running uv sync results in:

Resolved 213 packages in 1ms
error: Distribution `pywin32==310 @ registry+https://pypi.org/simple` can't be installed because it doesn't have a source distribution or wheel for the current platform

hint: You're using CPython 3.14 (`cp314`), but `pywin32` (v310) only has wheels with the following Python ABI tags: `cp311`, `cp312`, `cp313`

In the above, commenting out PyWinCtl will work.

Platform

Windows 10.0.19045 Build 19045

Version

uv 0.7.9 (13a86a2 2025-05-30)

Python version

Python 3.14.0a7

[oconnor663]

I'd like to try to reproduce this, but I need a little more hand-holding 😅 Could you tell me exactly how to get that artifact from https://github.com/mhammond/pywin32/actions/runs/15353580238 ?

[oconnor663]

Ah, @konstin helped me put together a Linux repro:

[project]
name = "debug"
version = "0.1.0"
requires-python = ">=3.12"
dependencies = [
  "pandas",
  "numpy; python_version < '3.13'",
]

[tool.uv.sources]
numpy = { url = "https://files.pythonhosted.org/packages/19/49/4df9123aafa7b539317bf6d342cb6d227e49f7a35b99c287a6109b13dd93/numpy-2.2.6-cp313-cp313-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", marker = "python_version >= '3.13'" }

$ uv run -p 3.12 --with pip python -m pip download pandas
...
$ uv run -p 3.13 --with pip python -m pip download pandas
...
$ rm numpy*cp313*
$ mkdir wheels
$ mv *.whl wheels
$ uv sync -p 3.12 --no-index --find-links wheels
... [works]
$ uv sync -p 3.13 --no-index --find-links wheels
...
error: Distribution `numpy==2.2.6 @ registry+wheels` can't be installed because it doesn't have a source distribution or wheel for the current platform

hint: You're using CPython 3.13 (`cp313`), but `numpy` (v2.2.6) only has wheels with the following Python ABI tag: `cp312`

Removing the dependency on pandas above fixes the last command.

[zanieb]

This behavior is intentional, afaik. We require all sources to be direct dependencies.

edit: ah I see this is both direct and transitive, sorry I misunderstood

[Avasam]

I'd like to try to reproduce this, but I need a little more hand-holding 😅 Could you tell me exactly how to get that artifact from mhammond/pywin32/actions/runs/15353580238 ?

When you scroll down to the bottom of the page you can download artifacts

But since you now have a linux based repro, that works too :) (and the source can probably be anything, like a url source)

[oconnor663]

Does removing the python_version marker from your [dependencies] list fix the issue? For example, the NumPy repro above works if I do this (hat tip @konstin again):

diff --git i/pyproject.toml w/pyproject.toml
index dfc8679..ee7206b 100644
--- i/pyproject.toml
+++ w/pyproject.toml
@@ -4,7 +4,7 @@ version = "0.1.0"
 requires-python = ">=3.12"
 dependencies = [
   "pandas",
-  "numpy; python_version < '3.13'",
+  "numpy",
 ]
 
 [tool.uv.sources]

I don't understand all the machinery here yet, but I think the sources feature works by "patching" your dependencies, and if the markers/constraints don't match/overlap between dependencies and sources, that "patch" has no effect?

[Avasam]

Does removing the python_version marker from your [dependencies] list fix the issue?

@oconnor663 Not only does it work, I didn't even realize that in my minimal example pywin32 isn't installed at all on 3.14

I don't understand all the machinery here yet, but I think the sources feature works by "patching" your dependencies, and if the markers/constraints don't match/overlap between dependencies and sources, that "patch" has no effect?

Sounds like that would be it.

---

Idk if there's ways to improve user messaging. Maybe detect and warn if a source in tool.uv.sources goes unused (taking into account the marker)? that would probably have tipped me off.

Feel free to close !

[oconnor663]

Yes I think adding a warning for cases like this would be a good idea. I'll keep this ticket open and try that today or tomorrow.

[zanieb]

Just to be clear, I don't think we can unconditionally warn if tool.uv.sources is unused at install time — it'd be too noisy. However, I do think it's reasonable to warn if tool.uv.sources would never be used. It seems a bit tricky, but maybe it's not so bad. @oconnor663, I'd recommend opening a new issue with a simpler reproduction and dedicated title so we can close this one out.

[oconnor663]

Opened #13829. Closing this one.