Based on the [Determinate Nix Installer](https://github.com/DeterminateSystems/nix-installer), responsible for over tens of thousands of Nix installs daily.
The fast, friendly, and reliable GitHub Action to install Nix with Flakes.
- ✅ **Accelerated KVM** on open source projects and larger runners. See [GitHub's announcement](https://github.blog/changelog/2023-02-23-hardware-accelerated-android-virtualization-on-actions-windows-and-linux-larger-hosted-runners/) for more info.
- ✅ Linux, x86_64, aarch64, and i686
- ✅ macOS, x86_64 and aarch64
- ✅ WSL2, x86_64 and aarch64
- ✅ Containers
- ✅ Valve's SteamOS
- ✅ GitHub Enterprise Server
- ✅ GitHub Hosted, self-hosted, and long running Actions Runners
| `backtrace` | The setting for [`RUST_BACKTRACE`][backtrace] | string | |
| `extra-args` | Extra arguments to pass to the planner (prefer using structured `with:` arguments unless using a custom [planner]!) | string | |
| `extra-conf` | Extra configuration lines for `/etc/nix/nix.conf` (includes `access-tokens` with `secrets.GITHUB_TOKEN` automatically if `github-token` is set) | string | |
| `flakehub` | Log in to FlakeHub to pull private flakes using the GitHub Actions [JSON Web Token](https://jwt.io) (JWT), which is bound to the `api.flakehub.com` audience. | Boolean | `false` |
| `force-docker-shim` | Force the use of Docker as a process supervisor. This setting is automatically enabled when necessary. | Boolean | `false` |
| `github-token` | A [GitHub token] for making authenticated requests (which have a higher rate-limit quota than unauthenticated requests) | string | `${{ github.token }}` |
| `github-server-url` | The URL for the GitHub server, to use with the `github-token` token. Defaults to the current GitHub server, supporting GitHub Enterprise Server automatically. Only change this value if the provided `github-token` is for a different GitHub server than the current server. | string | `${{ github.server }}` |
| `init` | The init system to configure (requires `planner: linux-multi`) | enum (`none` or `systemd`) | |
| `kvm` | Automatically configure the GitHub Actions Runner for NixOS test support, if the host supports it. | Boolean | `true` |
| `local-root` | A local `nix-installer` binary root. Overrides the `nix-installer-url` setting (a `nix-installer.sh` should exist, binaries should be named `nix-installer-$ARCH`, eg. `nix-installer-x86_64-linux`). | Boolean | `false` |
| `log-directives` | A list of [tracing directives], comma separated with `-`s replaced with `_` (eg. `nix_installer=trace`) | string | |
| `logger` | The logger to use during installation | enum (`pretty`, `json`, `full`, `compact`) | |
| `mac-case-sensitive` | Use a case-sensitive volume (`planner: macos` only) | Boolean | `false` |
| `mac-encrypt` | Force encryption on the volume (`planner: macos` only) | Boolean | `false` |
| `mac-root-disk` | The root disk of the target (`planner: macos` only) | string | |
| `mac-volume-label` | The label for the created [APFS] volume (`planner: macos` only) | string | |
| `modify-profile` | Modify the user [profile] to automatically load Nix | Boolean | `false` |
| `nix-build-group-id` | The Nix build group GID | integer | |
| `nix-build-group-name` | The Nix build group name | string | |
| `nix-build-user-base` | The Nix build user base UID (ascending) | integer | |
| `nix-build-user-count` | The number of build users to create | integer | 32 |
| `nix-build-user-prefix` | The Nix build user prefix (user numbers will be postfixed) | string | |
| `source-branch` | The branch of `nix-installer` to use (conflicts with the `source-tag`, `source-revision`, and `source-branch`) | string | |
| `source-pr` | The pull request of `nix-installer` to use (conflicts with `source-tag`, `source-revision`, and `source-branch`) | integer | |
| `source-revision` | The revision of `nix-installer` to use (conflicts with `source-tag`, `source-branch`, and `source-pr`) | string | |
| `source-tag` | The tag of `nix-installer` to use (conflicts with `source-revision`, `source-branch`, `source-pr`) | string | |
| `source-url` | A URL pointing to a `nix-installer.sh` script | URL | `https://install.determinate.systems/nix` |
| `planner` | The installation [planner] to use | enum (`linux` or `macos`) | |
| `reinstall` | Force a reinstall if an existing installation is detected (consider backing up `/nix/store`) | Boolean | `false` |
| `start-daemon` | If the daemon should be started, requires `planner: linux-multi` | Boolean | `false` |
| `trust-runner-user` | Whether to make the runner user trusted by the Nix daemon | Boolean | `true` |
| `diagnostic-endpoint` | Diagnostic endpoint url where the installer sends install [diagnostic reports](https://github.com/DeterminateSystems/nix-installer#diagnostics) to, to disable set this to an empty string | string | `https://install.determinate.systems/nix-installer/diagnostic` |
| `proxy` | The proxy to use (if any), valid proxy bases are `https://$URL`, `http://$URL` and `socks5://$URL` | string | |
| `ssl-cert-file` | An SSL cert to use (if any), used for fetching Nix and sets `NIX_SSL_CERT_FILE` for Nix | string | |
