title: docker-compose selectively thinks config.yml is a folder
body: <p>I am running docker-compose 1.25.5 on a ubuntu 20 box and I have a github repo working "fine" in its home folder... I can docker-compose build and docker-compose up with no problem, and the container does what is expected. The github repo is current with the on-disk files.</p>
  
  <p>As a test, however, I created a new folder, pulled the repo, and ran docker-compose build with no problem but when I tried to run docker-compose up, I get the following error: </p>
  
  <pre><code>Starting live_evidently_1 ... done
  Attaching to live_evidently_1
  evidently_1  | Traceback (most recent call last):
  evidently_1  |   File "app.py", line 14, in &lt;module&gt;
  evidently_1  |     with open('config.yml') as f:
  evidently_1  | IsADirectoryError: [Errno 21] Is a directory: 'config.yml'
  live_evidently_1 exited with code 1
  </code></pre>
  
  <p>config.yml on my host is a file (of course) and the docker-compose.yml file is unremarkable:</p>
  
  <pre><code>version: "3"
  
  services:
    evidently:
      build: ../
      volumes:
        - ./data:/data
        - ./config.yml:/app/config.yml
  </code></pre>
  
  <p>etc...
  ...</p>
  
  <p>So, I am left with two inter-related problems. 1) Why does the test version of the repo fail and the original version is fine (git status is unremarkable, all the files I want on github are up to date), and 2) Why does docker-compose think that config.yml is a folder when it is clearly a file?   I would welcome suggestions.</p>