[BUG] uv add does not consider the python version when resolving dependency versions

[TonyYanOnFire]

I encountered an error when running the following command:

$ uv add pandas==2.0.3
× No solution found when resolving dependencies for split (python_full_version >= '3.11'):
╰─▶ Because only the following versions of numpy{python_full_version >= '3.11'} are available:
numpy{python_full_version >= '3.11'}<=2.0.2
numpy{python_full_version >= '3.11'}>=2.1.0
and pandas==2.0.3 depends on numpy{python_full_version >= '3.11'}>=1.23.2, we can conclude that pandas==2.0.3 depends on one of:
numpy>=1.23.2,<=2.0.2
numpy>=2.1.0

And because your project depends on numpy==1.21.6 and pandas==2.0.3, we can conclude that your project's requirements are unsatisfiable.
help: If you want to add the package regardless of the failed resolution, provide the `--frozen` flag to skip locking and syncing.

My pyproject.toml already specifies the Python version:

[project]
...
requires-python = ">=3.8"

My runtime environment is also Python 3.8.

The dependency requirements for pandas 2.0.3 are as follows, as referenced in https://github.com/pandas-dev/pandas/blob/v2.0.3/pyproject.toml:

dependencies = [
"numpy>=1.20.3; python_version<'3.10'",
"numpy>=1.21.0; python_version>='3.10'",
"numpy>=1.23.2; python_version>='3.11'",
"python-dateutil>=2.8.2",
"pytz>=2020.1",
"tzdata>=2022.1"
]

My current numpy==1.21.6 should meet the installation requirements for pandas==2.0.3 under Python 3.8. It seems uv is checking requirements for Python 3.11 which seems like a bug

[TonyYanOnFire]

pip install pandas==2.0.3 works just fine

Requirement already satisfied: numpy>=1.20.3 in ...\.venv\lib\site-packages (from pandas==2.0.3) (1.21.6)

[charliermarsh]

This is all working as intended. With requires-python = ">=3.8", we need to resolve for all Python versions later than 3.8, not just 3.8 itself. But given your requirements, there's no valid resolution for Python 3.11, for example.

You can set requires-python = ">=3.8, <3.9", for example, to limit the range of supported versions in your project.

[TonyYanOnFire]

Thanks @charliermarsh

I took your suggestion, set requires-python = ">=3.8, <3.9" and then ran uv add pandas==2.0.3 . It works fine.

Regarding the strategy for uv to resolve dependencies when requires-python = ">=3.8". as you mentioned, I tried searching in the documentation, but could not find any corresponding discussion. If such a chapter exists in the documentation, it would be great if you could provide the source.

By the way, my pyproject.toml file (and requires-python = ">=3.8" in it) was created by running uv init when trying to introduce uv into an existing project. In such a scenario, I think setting require -python to >=3.8, <3.9 may be more convenient for people like me who are new to UV