detect_sha_changes.yml

name: Detect changes to header SHAs

on:
  pull_request:

jobs:
  build:
    name: Add annotations
    runs-on: ubuntu-latest
    env:
      GH_TOKEN: ${{ github.token }}
    steps:
      - name: "Checkout mathlib4"
        uses: actions/checkout@v4

      - name: "Checkout mathlib3"
        uses: actions/checkout@v4
        with:
          repository: leanprover-community/mathlib
          path: port-repos/leanprover-community/mathlib

      - name: "Checkout lean3"
        uses: actions/checkout@v4
        with:
          repository: leanprover-community/lean
          path: port-repos/leanprover-community/lean

      - name: Fetch merge base SHA from API
        run: |
          my_merge_base_cmd="gh api repos/${{ github.repository }}/compare/${{ github.event.pull_request.base.sha }}...${{ github.event.pull_request.head.sha }} | jq -r '.merge_base_commit.sha'"
          echo "${my_merge_base_cmd}"
          my_merge_base="$(eval "${my_merge_base_cmd}")"
          printf 'MY_MERGE_BASE_SHA=%s\n' "${my_merge_base}" >> "${GITHUB_ENV}"

      - name: Fetch merge base SHA
        run: |
          git fetch \
            --no-tags \
            --prune \
            --progress \
            --no-recurse-submodules \
            --depth=1 \
            origin "${MY_MERGE_BASE_SHA}"

      - name: install Python
        uses: actions/setup-python@v4
        with:
          python-version: 3.8

      - name: install script dependencies
        run: |
          pip install gitpython

      - name: run the script
        run: |
          python scripts/detect_sha_changes.py "${MY_MERGE_BASE_SHA}" "HEAD"