action-setup-lix

This GitHub Action installs Lix in single-user mode, and adds almost no time at all to your workflow's running time.

The Lix installation is deterministic – for a given release of this action the resulting Lix setup will always be identical, no matter when you run the action.

• Supports all Linux and MacOS runners

• Single-user installation (no nix-daemon)

• Installs in ≈ 1 second on Linux, ≈ 5 seconds on MacOS

• Allows selecting Lix version via the lix_version input

• Allows specifying nix.conf contents via the nix_conf input

Details

The main motivation behind this action is to install Lix as quickly as possible in your GitHub workflow.

To make this action as quick as possible, the installation is minimal: no nix-daemon, no nix channels and no NIX_PATH. The nix store (/nix/store) is owned by the unprivileged runner user.

The action provides you with a fully working Lix setup, but since no NIX_PATH or channels are setup you need to handle this on your own. Lix Flakes is great for this, and works perfectly with this action (see below).

Inputs

TODO: Generate inputs table.

Usage

The following workflow installs Lix and then just runs nix-build --version:

---
name: Examples / Minimal
on: workflow_dispatch
permissions: {}
jobs:
  example:
    runs-on: ubuntu-latest
    steps:
      - uses: fabrictest/action-setup-lix@d5d7d9aa579140ff7b9b64c02766ed55bb80c3f8 # v0.15.0
      - run: nix build --version

Flakes

These settings are always set by default:

experimental-features = nix-command flakes
accept-flake-config = true

---
name: Examples / Flakes
on: workflow_dispatch
permissions: {}
jobs:
  example:
    runs-on: ubuntu-latest
    steps:
      - uses: fabrictest/action-setup-lix@d5d7d9aa579140ff7b9b64c02766ed55bb80c3f8 # v0.15.0
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
        with:
          repository: fabrictest/action-setup-lix
          persist-credentials: false
      - run: nix build ./examples/flakes
      - run: ./result/bin/hello

You can see the flake definition for the above example in examples/flakes/flake.nix.

Using specific Lix versions locally

Locally, you can use this repository's Lix flake to build or run any of the versions of Lix that this action supports. This is very convenient if you quickly need to compare the behavior between different Lix versions.

Build a specific version of Lix like this (requires you to use a version of Lix that supports flakes):

nix build github:fabrictest/action-setup-lix#lix-2_91_1 >/dev/null
./result/bin/nix --quiet --version

nix (Lix, like Nix) 2.91.1

You can also directly run Lix with nix shell -c:

nix shell --no-write-lock-file github:fabrictest/action-setup-lix#lix-2_91_1 -c nix --quiet --version

List all available Lix versions with:

nix flake show --all-systems github:fabrictest/action-setup-lix/v0.15.0

github:fabrictest/action-setup-lix/…
├───__functor: unknown
├───__std: unknown
├───aarch64-darwin: unknown
├───aarch64-linux: unknown
├───devShells
│   ├───aarch64-darwin
│   │   └───default: development environment 'action-setup-lix'
│   ├───aarch64-linux
│   │   └───default: development environment 'action-setup-lix'
│   ├───x86_64-darwin
│   │   └───default: development environment 'action-setup-lix'
│   └───x86_64-linux
│       └───default: development environment 'action-setup-lix'
├───overlays
│   └───lixPackages: Nixpkgs overlay
├───packages
│   ├───aarch64-darwin
│   │   ├───default: package 'lix-stores'
│   │   ├───lix-2_90_0: package 'lix-2.90.0' - 'Powerful package manager that makes package management reliable and reproducible'
│   │   ├───lix-2_91_1: package 'lix-2.91.1' - 'Powerful package manager that makes package management reliable and reproducible'
│   │   └───lix-stores: package 'lix-stores'
│   ├───aarch64-linux
│   │   ├───default: package 'lix-stores'
│   │   ├───lix-2_90_0: package 'lix-2.90.0' - 'Powerful package manager that makes package management reliable and reproducible'
│   │   ├───lix-2_91_1: package 'lix-2.91.1' - 'Powerful package manager that makes package management reliable and reproducible'
│   │   └───lix-stores: package 'lix-stores'
│   ├───x86_64-darwin
│   │   ├───default: package 'lix-stores'
│   │   ├───lix-2_90_0: package 'lix-2.90.0' - 'Powerful package manager that makes package management reliable and reproducible'
│   │   ├───lix-2_91_1: package 'lix-2.91.1' - 'Powerful package manager that makes package management reliable and reproducible'
│   │   └───lix-stores: package 'lix-stores'
│   └───x86_64-linux
│       ├───default: package 'lix-stores'
│       ├───lix-2_90_0: package 'lix-2.90.0' - 'Powerful package manager that makes package management reliable and reproducible'
│       ├───lix-2_91_1: package 'lix-2.91.1' - 'Powerful package manager that makes package management reliable and reproducible'
│       └───lix-stores: package 'lix-stores'
├───x86_64-darwin: unknown
└───x86_64-linux: unknown

If you want to make sure that the version of Lix you're trying to build hasn't been removed in the latest revision of action-setup-lix, you can specify a specific release of action-setup-lix like this:

nix build github:fabrictest/action-setup-lix/v0.15.0#lix-2_91_1

Note that we've added /v0.15.0 to the flake URL above.

Credits

TODO