Uses pip's API

Implements uninstall

Tracks uninstalled packages

Detects failures

Implements rollback

Handles command-line arguments

VCS URL parsing

Revision extraction

Subdirectory parsing

Pip command construction

Editable installation

VCS installation execution

Uses --target flag

Uses --user flag

Subprocess invocation

Correct return values

Proper error handling

Cache directory retrieval

Cache statistics

List cached items

Pattern-based filtering

Remove cached items

Purge all cache

Error handling

pip wheel usage

Local source handling

PyPI package handling

Output directory specification

Build result tracking

Error handling

Package discovery

Metadata extraction

Outdated detection

Installation filtering

Columnar output

Freeze format

JSON output

Subprocess invocation

--only-binary flag

--no-binary flag

--prefer-binary flag

--target flag

Installation detection

Version detection

URL credential parsing

.netrc integration

Keyring integration

Credential precedence

Package download

Multi-index support

Uses pip hash APIs

Supports multiple algorithms

Hash format compatibility

Efficient file processing

Error handling alignment

Uses pip download

Destination directory specification

Requirements file handling

Platform-specific downloads

Resume capability