This fixes a regression from 0.8.0 from https://github.com/astral-sh/uv/pull/7934 and follows https://github.com/astral-sh/uv/pull/15059 The regression is from [this change](https://github.com/astral-sh/uv/pull/7934/files#diff-c7a660ac39628d5e12f388b0cacc7360affa3d7bb21191184d7ee78489675e83), which was made because we'd otherwise (with the other changes in that pull request) _filter out_ managed Python interpreters found in virtual environments. When `--system` is used we'll convert the default Python preference of `managed` to `system` which avoids things like `uv pip install --system` targeting a managed Python installation. The basic test is ``` uv python install uv pip install --system anyio ``` Prior to this change, we'd read a managed interpreter from our managed installation directory and target that. After this change, without #15059, we'd read a managed interpreter from the PATH and target that. Both of those experiences are bad, because the managed interpreters are marked as externally managed. After this change, with #15059, we properly target the system interpreter. Since we use `system` instead of `only-system`, if there is not a system interpreter we'll still retain our existing behavior and use a managed interpreter. This should limit breakage from the change. Given the source of the regression, we could probably use `only-system` here. I don't feel strongly. I think the main benefit of doing so would be that we'd omit the check for managed installations in error messages when an interpreter cannot be found? We can't really add test coverage here because the test suite always has externally managed interpreters :)
Crates
uv-bench
Functionality for benchmarking uv.
uv-cache-key
Generic functionality for caching paths, URLs, and other resources across platforms.
uv-distribution-filename
Parse built distribution (wheel) and source distribution (sdist) filenames to extract structured metadata.
uv-distribution-types
Abstractions for representing built distributions (wheels) and source distributions (sdists), and the sources from which they can be downloaded.
uv-install-wheel-rs
Install built distributions (wheels) into a virtual environment.
uv-once-map
A waitmap-like concurrent hash map for executing tasks
exactly once.
uv-pep440-rs
Utilities for interacting with Python version numbers and specifiers.
uv-pep508-rs
Utilities for parsing and evaluating dependency specifiers, previously known as PEP 508.
uv-platform-tags
Functionality for parsing and inferring Python platform tags as per PEP 425.
uv-cli
Command-line interface for the uv package manager.
uv-build-frontend
A PEP 517-compatible build frontend for uv.
uv-cache
Functionality for caching Python packages and associated metadata.
uv-client
Client for interacting with PyPI-compatible HTTP APIs.
uv-dev
Development utilities for uv.
uv-dispatch
A centralized struct for resolving and building source distributions in isolated environments.
Implements the traits defined in uv-types.
uv-distribution
Client for interacting with built distributions (wheels) and source distributions (sdists). Capable of fetching metadata, distribution contents, etc.
uv-extract
Utilities for extracting files from archives.
uv-fs
Utilities for interacting with the filesystem.
uv-git
Functionality for interacting with Git repositories.
uv-installer
Functionality for installing Python packages into a virtual environment.
uv-python
Functionality for detecting and leveraging the current Python interpreter.
uv-normalize
Normalize package and extra names as per Python specifications.
uv-requirements
Utilities for reading package requirements from pyproject.toml and requirements.txt files.
uv-resolver
Functionality for resolving Python packages and their dependencies.
uv-shell
Utilities for detecting and manipulating shell environments.
uv-types
Shared traits for uv, to avoid circular dependencies.
uv-pypi-types
General-purpose type definitions for types used in PyPI-compatible APIs.
uv-virtualenv
A venv replacement to create virtual environments in Rust.
uv-warnings
User-facing warnings for uv.
uv-workspace
Workspace abstractions for uv.
uv-requirements-txt
Functionality for parsing requirements.txt files.