dist-dependency-cache.yml

name: Dist Dependency Cache

# Saves the compiled dependencies that the macOS wheel jobs of Build Distributions restore for
# release builds. Only this workflow saves them, and only on main, so every release-please branch
# and release tag can read them while no pull request or release run can write them. It builds the
# macOS legs only when main has no cache for the current lockfile and toolchain. It has its own
# concurrency group because a cold macOS dist build takes about an hour, which must not hold back
# the Verify caches that Rust Build Cache refreshes.
on:
  push:
    branches: [main]
  # A new stable toolchain changes the key without a push to main.
  schedule:
    - cron: "30 4 * * *"

permissions:
  contents: read

concurrency:
  group: dist-dependency-cache-${{ github.ref }}
  cancel-in-progress: false

jobs:
  lookup:
    name: Look up the macOS caches
    runs-on: macos-15
    timeout-minutes: 15
    outputs:
      missing: >-
        ${{ steps.arm64.outputs.cache-hit != 'true' || steps.x86_64.outputs.cache-hit != 'true' }}
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@master
        with:
          toolchain: stable
      # The keys must match the restore step of the Build Distributions wheel jobs.
      - name: Look up the macOS arm64 cache
        id: arm64
        uses: Swatinem/rust-cache@v2
        with:
          shared-key: dist-macos-arm64-dist
          lookup-only: true
          save-if: false
      - name: Look up the macOS x86_64 cache
        id: x86_64
        uses: Swatinem/rust-cache@v2
        with:
          shared-key: dist-macos-x86_64-dist
          lookup-only: true
          save-if: false

  distributions:
    name: macOS dist dependencies
    needs: lookup
    if: needs.lookup.outputs.missing == 'true'
    uses: ./.github/workflows/build-distributions.yml
    with:
      sdist: false
      dependency-cache-writer: true