f615e81ad5
## Summary This PR removes the ephemeral `.pth` overlay when using a cached environment. This solution isn't _completely_ safe, since we could remove the `.pth` file just as another process is starting the environment... But that risk already exists today, since we could _overwrite_ the `.pth` file just as another process is starting the environment, so I think what I've added here is a strict improvement. Ideally, we wouldn't write this file at all, and we'd instead somehow (e.g.) pass a file to the interpreter to run at startup? Or find some other solution that doesn't require poisoning the cache like this. Closes https://github.com/astral-sh/uv/issues/11117. # Test Plan Ran through the great reproduction steps from the linked issue. Before:  After: 
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.