cached git submodules but get a warning "fatal: not a git repository"

[adoyle-h]

I use actions/cache to cache all git submodules. But get a warning at POST RUN actions/checkout.

I want to reuse the caches of submodules, so .git/modules/test/fixture/assert should be empty.
So how to fix these warnings?

Is there any option to skip submodules when actions/checkout run /usr/bin/git submodule foreach?

My workflow steps:

    steps:
      - uses: actions/checkout@v3

      - name: Cache test/fixture
        id: cache-test-fixture
        uses: actions/cache@v3
        with:
          path: |
            test/fixture/assert
            test/fixture/bats
            test/fixture/bats-file
            test/fixture/support
          key: ${{ runner.os }}-test-fixture

      - name: Update git submodules
        if: steps.cache-test-fixture.outputs.cache-hit != 'true'
        run:
          git submodule update --init --recursive

.gitmodules:

[submodule "test/fixture/bats"]
	path = test/fixture/bats
	url = https://github.com/bats-core/bats-core.git
  shallow = true
[submodule "test/fixture/assert"]
	path = test/fixture/assert
	url = https://github.com/bats-core/bats-assert.git
  shallow = true
[submodule "test/fixture/bats-file"]
	path = test/fixture/bats-file
	url = https://github.com/bats-core/bats-file.git
  shallow = true
[submodule "test/fixture/support"]
	path = test/fixture/support
	url = https://github.com/bats-core/bats-support.git
  shallow = true

[vpavlin]

Also hitting this - is it not possible to cache submodules?

[oerp-odoo]

I am using it this way:

      - name: Checkout myrepo
        uses: actions/checkout@v3
      - name: Cache Submodules
        id: cache-submodule
        uses: actions/cache@v3
        with:
          path: |
            my/sub1
            my/sub2
          key: ${{ runner.os }}-submodules
      - name: Update git submodules
        if: steps.cache-submodule.outputs.cache-hit != 'true'
        uses: actions/checkout@v3
        with:
          submodules: recursive

I get same warning, but it looks like caching still works