Provides a generic RunCommand function that executes external commands with configurable timeout, process group management (Unix), and automatic cleanup of descendant processes on timeout or interrupt. It uses signal notification context and WaitDelay to ensure subprocesses are killed even if they retain output pipes. This is a reusable pattern for any Go project that needs to run external commands with robust lifecycle management.

Implements a LatestRelease function that fetches the latest GitHub release for a given repository using the GitHub API. It configures an HTTP client with a 30-second response header timeout but no body deadline, allowing slow responses to complete. Supports authentication via GH_TOKEN environment variable. This is a clean, reusable component for any Go project that needs to interact with GitHub releases.

Provides an editPackage function that reads a Nix expression file, applies modifications via a callback, and saves atomically with rollback on failure. It uses regex-based replacement for version, URL, and hash fields, and supports block-level replacements for source definitions. The atomic write pattern (write to temp file, rename) ensures partial updates don't corrupt the file. This pattern is reusable for any project that needs to programmatically update configuration files with safe rollback.