`uv pip list` shows system python packages instead of `.venv` python packages

[taoari]

Summary

uv pip list shows the wrong (system python) environment:

> uv pip list
Using Python 3.11.5 environment at: D:\scoop\apps\anaconda3\current\App
Package                       Version
----------------------------- ---------------
aiobotocore                   2.5.0

The following one should be the correct one:

> .venv\Scripts\python -m pip list
Package                      Version   Editable project location
---------------------------- --------- ------------------------------------------------------
annotated-types              0.7.0

Platform

windows

Version

uv 0.8.14 (af856fb 2025-08-28)

Python version

Python 3.12.11

[charliermarsh]

It looks like you have an active Anaconda environment? What do the CONDA_PREFIX and VIRTUAL_ENV vars show?

[taoari]

@charliermarsh Here are the environment variables. I do have the base Anaconda environment activated by default, but shouldn't uv pip list prioritize the .venv folder over the base environment?

> $Env:CONDA_PREFIX
D:\scoop\apps\anaconda3\current\App

> $Env:VIRTUAL_ENV

[gigberg]

the same issue in the same time, uv pip's logic is a little wired. releated to #7124

see also:

An activated virtual environment based on the VIRTUAL_ENV environment variable.
An activated Conda environment based on the CONDA_PREFIX environment variable.
A virtual environment at .venv in the current directory, or in the nearest parent directory.
If no virtual environment is found, uv will prompt the user to create one in the current directory via uv venv.
If the --system flag is included, uv will skip virtual environments search for an installed Python version.

https://docs.astral.sh/uv/pip/environments/#discovery-of-python-environments

However, you can use uv pip install --python .venv/bin/python to let pip use your venv.

[zanieb]

@taoari what is CONDA_DEFAULT_ENV set to?

We do special-case base Conda environments, but we don't recognize the name "App" today.

uv/crates/uv-python/src/virtualenv.rs

Lines 79 to 106 in 3f83390

	impl CondaEnvironmentKind {
	/// Whether the given `CONDA_PREFIX` path is the base Conda environment.
	///
	/// When the base environment is used, `CONDA_DEFAULT_ENV` will be set to a name, i.e., `base` or
	/// `root` which does not match the prefix, e.g. `/usr/local` instead of
	/// `/usr/local/conda/envs/<name>`.
	fn from_prefix_path(path: &Path) -> Self {
	// If we cannot read `CONDA_DEFAULT_ENV`, there's no way to know if the base environment
	let Ok(default_env) = env::var(EnvVars::CONDA_DEFAULT_ENV) else {
	return Self::Child;
	};
	// These are the expected names for the base environment
	if default_env != "base" && default_env != "root" {
	return Self::Child;
	}
	let Some(name) = path.file_name() else {
	return Self::Child;
	};
	if name.to_str().is_some_and(|name| name == default_env) {
	Self::Base
	} else {
	Self::Child
	}
	}
	}

Why is your base environment called "App"?

[taoari]

@zanieb $Env:CONDA_DEFAULT_ENV
base

Anaconda base environemnt is located at anaconda3\current\App by default I think.

[zanieb]

Really? I thought the path usually matched the CONDA_DEFAULT_ENV name? What other directories are in that folder?

[taoari]

@zanieb Conda environments you create yourself usually match the directory name, like envs/<name>. The base environment is a special case.

> conda env list
# conda environments:
#
base                  *  D:\scoop\apps\anaconda3\current\App
python312                D:\scoop\apps\anaconda3\current\App\envs\python312

This is a bit off-topic — the actual issue is that uv pip seems to get the priority order wrong.

[zanieb]

It's not really off topic, because we use a different order if we can detect it's the base environment

[zanieb]

e.g., see #7691

and prior discussions in

• Reconsider priority of CONDA_PREFIX when discovering virtual environments #8940
• Enhancement: Change order of discovery of python environments for uv pip install  #7124
• Treat base conda environment as though it was a system Python #7137

[zanieb]

It seems like there is a mistake in the heuristic we're using.

[gigberg]

It seems like there is a mistake in the heuristic we're using.

Not really, the path format \"$dir\\App\\envs\" is caused by scoop, a windows package manager. I guess the op install anaconda by command scoop install extras/anaconda3. see as

"Start-Process \"$dir\\$fname\" -ArgumentList @('/S', '/InstallationType=JustMe', '/RegisterPython=1', '/AddToPath=0', '/NoRegistry=1', \"/D=$dir\\App\") -Wait

https://github.com/ScoopInstaller/Extras/blob/master/bucket/anaconda3.json#L23-L24

[gigberg]

Yes, this seems to be wrong, my ubuntu miniconda base path is $CONDA_PREFIX=~/miniconda not ~/miniconda/base or $CONDA_PREFIX=~/miniconda3/envs/labelyolo like special common envs.

uv/crates/uv-python/src/virtualenv.rs

Lines 96 to 98 in 3f83390

	let Some(name) = path.file_name() else {
	return Self::Child;
	};

Ubuntu 22.04, miniconda3:
env_name base:
$CONDA_PREFIX=~/miniconda
$echoCONDA_DEFAULT_ENV=base

env_name xxx
$CONDA_PREFIX=~/miniconda/envs/xxx
$echoCONDA_DEFAULT_ENV=xxx

So, maybe use

fn from_prefix_path(path: &Path) -> CondaEnvironmentKind {
    // Check whether the path contains a directory named "envs"
    if path.components().any(|comp| comp.as_os_str() == "envs") {
        // If "envs" is part of the path, it's a child environment
        CondaEnvironmentKind::Child
    } else {
        // Otherwise, it's the base environment
        CondaEnvironmentKind::Base
    }
}