allow "uv run" to work without a project

[mmerickel]

It'd be nice if this flow worked simply to avoid needing to activate a virtualenv - regardless of whether I'm using a full uv project or not.

$ uv venv
$ uv pip install -e .
$ uv run python

However as of 0.4.28 I get the following error:

$ uv run python
error: No `project` table found in: `/Users/michael/work/oss/webob/pyproject.toml`

Obviously in this case I'm not asking uv to do anything except use the correct path as if I was activating the virtualenv - equivalent to .venv/bin/activate; python.

[zanieb]

uv run --no-project should work there

[mmerickel]

Yeah thanks for pointing that out and I confirmed it works. Having to add an extra arg there on every command is a deal breaker right - uv run is the primary command I’m using all the time during dev. I’d instead activate the env or use .venv/bin/python … (my current flow). I guess this issue becomes a feature request to drop the flag and make it the default fallback behavior when no project can be found.

[zanieb]

What are you using the pyproject.toml for? Just want to understand the use-case more.

[mmerickel]

Things like build-system, black config, isort config, and tool.ruff config.

[zanieb]

What build system are you using without a [project] table 👀

[mmerickel]

setuptools doesn’t require it - it can pull all the data from setup.py and setup.cfg like it has for decades. :-) I guess I should switch it up to use project but it’s not required by the build backend PEP.

[mmerickel]

To be clear I know it’s required to use uv sync and uv lock + lock files but that’s not my short term goal.

[samypr100]

Having to add an extra arg there on every command is a deal breaker right - uv run is the primary command I’m using all the time during dev

Maybe as an alternative workaround, setup an shell alias for uv run to be uv run --no-project?

[mmerickel]

Yeah I can work around it, but this ticket is here incase y'all want a cleaner story for the larger community for "older" projects.

In pyramid we have for years recommended for people to do the following as a simple starter sequence:

python3 -m venv env
env/bin/pip install -e .
env/bin/pshell site.ini

And I thought it'd be cool to at least have a "drop in replacement" story for uv where we'd recommend the following:

uv venv
uv pip install -e .
uv run pshell site.ini

As of today we need to add --no-project to every uv run command and that's no fun. :-) Personally I think the error that is raised about "no project table" is not worth requiring an explicit flag to get past compared to the logical fallback to just run the command in the virtualenv even if there's no project.

Also mainly for my sanity and to clarify for anyone else I went back to just check and this issue occurs whether or not you have a pyproject.toml. It's just complaining about the missing [project] section therein.

[zanieb]

Fwiw I think this should probably work but doesn't

❯ cat pyproject.toml
[tool.uv]
managed = false

❯ uv run python
error: No `project` table found in: `/Users/zb/workspace/uv/example/pyproject.toml`

[mattp-]

👍 on this, I use uv primarily as a manager to venv's per project, but im not necessarily making changes to the projects im dropping into that would allow me to modify pyproject.toml. Being able to set an env var that silences no-project, but still works when a project dir i go to actually DOES have project settings, would be ideal.

[matterhorn103]

If a directory contains nothing but a script, with no pyproject.toml or .venv in sight, uv run script.py works.

If there's a .venv but no pyproject.toml, it also works.

Is that the intended behaviour? If so it seems strange to require a [project] table when pyproject.toml is present, but not otherwise.