GitHub Actions Runner Images

A CI/CD and automation platform from GitHub (Microsoft) that runs YAML-defined workflows in response to repository events, schedules, or API calls. Workflows orchestrate jobs on GitHub-hosted or self-hosted runners (Ubuntu, Windows, macOS or custom runners), invoke container, JavaScript or composite actions, and produce artifacts (build outputs, test reports, generated files). It supports secrets, caching, matrix and reusable workflows, the Actions Marketplace, and can run arbitrary CLI tools (for example, invoking a D2 CLI in a workflow to generate architecture diagrams from D2 source files).

actions/checkout is a GitHub Actions action that checks a repository out into the workflow’s `$GITHUB_WORKSPACE` directory for use by subsequent steps. It can select a repository and ref, perform shallow or complete-history fetches, sparse or partial checkouts, and fetch submodules, Git LFS files, tags, and authenticated content. By default, it fetches only the commit for the event’s triggering ref or SHA; `fetch-depth: 0` retrieves all branches and tags. Authentication can use a token or SSH key configured in the local Git configuration and removed during post-job cleanup; recent releases store persisted credentials in a separate file under `$RUNNER_TEMP`. If Git 2.18 or newer is unavailable, the action falls back to the GitHub REST API to download files. Checkout v7 migrates the action to ESM, updates direct and transitive dependencies, and refuses fork pull-request code by default for workflows triggered by `pull_request_target` or `workflow_run`, which have access to the base repository’s token, secrets, and runner. Reviewed exceptions can opt in with `allow-unsafe-pr-checkout: true`.

Kakehashi is a userspace macOS ARM64-to-Linux aarch64 translation layer for running Darwin Mach-O command-line binaries on ARM64 Linux without a virtual machine, JIT compiler, or instruction emulator. It loads Mach-O files, maps a freestanding libSystem environment, and translates BSD system calls at the guest–host boundary while handling guest threads and faults. The CLI provides live execution through `kh run` on Linux aarch64, plus a dry-load mode available on other hosts. It requires a manually assembled macOS guest filesystem, called a bottle, at the fixed path `~/.local/share/kakehashi/bottle/`; the project documents copying core directories from macOS and installing Apple Xcode Command Line Tools into the bottle. The repository states that the project is no longer maintained.

GitHub CLI is GitHub's official command-line tool, developed for GitHub.com, GitHub Enterprise Cloud, and GitHub Enterprise Server. The `gh` command brings pull requests, issues, and other GitHub concepts into the terminal alongside Git and source code, including workflows for authenticating an account, creating repositories and branches, pushing changes, and opening draft pull requests. It supports macOS, Windows, and Linux, and an agent skill is available for driving `gh` from coding agents.

Google Cloud Build is a managed continuous integration and continuous delivery service that executes build steps to compile source code, build deployment containers, run tests, and produce deployable artifacts. It can build from repositories and trigger pipelines from source changes, with configuration defined in build files.