title: ERROR: Service 'dash' failed to build: COPY failed: stat /var/lib/docker/tmp/docker-builder134733065/app.py: no such file or directory in Windows 10
body: <p>My docker-compose.yml file:</p>
  
  <pre><code>version: '3'
  services:
    dash:
      build: ./docker
      environment:
        - COMPOSE_CONVERT_WINDOWS_PATHS=false
      ports:
        - "5000:5000"
      volumes:
        - c:/Users:/data
  </code></pre>
  
  <ul>
  <li>Dockerfile</li>
  </ul>
  
  <pre><code>FROM python:3
  
  WORKDIR /data
  
  COPY requirements.txt ./
  RUN pip install --no-cache-dir -r requirements.txt
  
  COPY app.py ./ 
  
  CMD [ "python", "./app.py" ]
  </code></pre>
  
  <p>doing a simple COPY command in Dockerfile is throwing this error when the file is in a folder (not same level as Dockerfile file)</p>
  
  <p>My folder structure:</p>
  
  <pre><code>- docker
      - Dockerfile
      - requirements.txt  
  - app
      - app.py
  - docker-compose.yml
  </code></pre>