nix-gh-cache.yml

# Build derivations for Linux and Apple Silicon and upload them to
# Cachix

name: Nix Cache

on:
  push:
    paths:
      - "**.nix"
      - "**.lock"
      - "**package.json"
      - "**pyproject.toml"
      - ".github/**.ya?ml"
  workflow_dispatch:

# Kill running jobs if a new commit is pushed to PR, or someone restarts
# a job that is already running.
concurrency:
  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
  cancel-in-progress: true

jobs:

  prime:
    name: Prime Cachix

    strategy:
      # Keep building other OSes even if one fails
      fail-fast: false
      matrix:
        # ubuntu-latest-16-cores: Hosted GHA Linux runner, larger than default
        #    so that this job primes the cache as much as possible before
        #    other jobs that depend on the cache start running
        # macos-latest: Hosted GHA Intel-based MAC runner
        # macos-m1: TODO, GitHub says they will be available in Q4
        os: [ubuntu-latest, macos-latest]
    runs-on: ${{ matrix.os }}

    steps:
      - uses: actions/checkout@v3
      - uses: ./.github/actions/nix-shell
        with:
          cachix_auth_token: '${{ secrets.CACHIX_AUTH_TOKEN_PUBLIC }}'