on: push

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      # These are listed
      - run: echo '${{ vars.FOO }}'
      - run: echo '${{ vars.WOO }}'
      # Name is case-insensitive
      - run: echo '${{ vars.foo }}'
      - run: echo '${{ vars.Foo }}'
      # ERROR: Undefined var
      - run: echo '${{ vars.PIYO }}'
