我的目录结构如下：

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

在deploy.yml中我有以下内容：

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

但是.它会失败，并出现以下错误
错误：无法求解：无法读取dockerfile：打开/tmp/构建工具包安装2199217382/停靠文件：没有这样的文件或目录错误：buildx失败，原因为：错误：无法求解：无法读取dockerfile：打开/tmp/构建工具包安装2199217382/停靠文件：没有这样的文件或目录
注意：如果我将app/中的所有内容移动到根目录，并按如下所示更改deploy.yml，那么一切都可以正常工作

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

有人能帮我找到这个相对路径的问题吗？