Docker Build Failed in Github Actions - failed to read dockerfile

I have the following Directory structure:

├── .github/workflows
│   ├── deploy.yml
├── app
│   ├── Dockerfile
│   ├── __init__.py
│   ├── main.py
│   ├── requirements.txt
      

And in the deploy.yml I have the following content:

name: TestJobs
on: [push]

jobs:

  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v2

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v1

      - name: Build and push
        uses: docker/build-push-action@v2
        with:
          context: ./app # even tried with just "app" without double quotation
          file: ./Dockerfile # even tried with just "Dockerfile" without double quotation
          tags: myimage:latest
          outputs: type=docker,dest=/tmp/myimage.tar

      - name: Upload artifact
        uses: actions/upload-artifact@v2
        with:
          name: myimage
          path: /tmp/myimage.tar

But. it fails with the following error

> ERROR: failed to solve: failed to read dockerfile: open /tmp/buildkit-mount2199217382/Dockerfile: no such file or directory
Error: buildx failed with: ERROR: failed to solve: failed to read dockerfile: open /tmp/buildkit-mount2199217382/Dockerfile: no such file or directory

Note: Evrything works fine if I moved all the content inside the app/ to the root directory and change the deploy.yml as below

. . .
      - name: Build and push
        uses: docker/build-push-action@v2
        with:
          context: .
          file: ./Dockerfile 
. . .

Can someone help me find the issue with this relative-path here?

Here my build steps:

      - name: Build and push Docker image
        uses: docker/build-push-action@v4
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}

or

      - name: Build and push Docker image
        uses: docker/build-push-action@v4
        with:
          context: .
          file: ./examples/Dockerfile
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}

In example one my docker file is at the root of my repo. In the second example my docker file its in a folder (like you) named example (your is app).so with that approach the following should work for you:

      - name: Build and push Docker image
        uses: docker/build-push-action@v4
        with:
          context: .
          file: ./app/Dockerfile
          push: true
          tags: myimage:latest
          outputs: type=docker,dest=/tmp/myimage.tar

context: app/

I think that may do it.