Docker-compose config: how to pass arguments

Docker Engine Compose
1

I’m not sure it’s correct, but I used to use
$ docker-compose config
to verify if final docker-compose configuration merged from multiple files is what I expected it to be.

The problem appears when I use arguments (ARG) in docker-compose.yml. docker-compose config shows in this case nothing, even if I pass default value.

Example docker-compose.yml:

services:
    web:
        build:
            args:
                - sync_path=C:\Users\abc\test
        volumes:
            - $sync_path:/path/to/folder

Example output using docker-compose config command:

services:
    web:
        build:
            args:
                - sync_path=C:\Users\abc\test
        volumes:
            - .:/path/to/folder    # <---- dot instead of path in sync_path!

Is there any way I can display args in docker-compose config or is there any better way to debug my docker-compose configuration?