on:
  pull_request_target

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          ref: ${{ github.event.pull_request.head.sha }}
      - id: artifact
        run: |
          echo "::set-output name=pr_number::$(<artifact.txt)"
      - name: Use artifact
        run: echo ${{ steps.artifact.outputs.pr_number }} 
