Explicitly mount files with docker-compose

When mounting files in docker compose, like this:

  - ./file-to-mount:/target/file-to-mount

an empty directory is created inside the container, if the file-to-mount does not exist! This leads to annoying debug sessions…

One can use the following syntax (with docker-compose 3.4), to mount a file more explicitly:

      - type: bind
        source: ./file-to-mount
        target: /target/file-to-mount

Now, when the file does not exists, it is not possible to start the container.

invalid mount config for type "bind": bind source path does not exist...