ERROR: In file './docker-compose.yml', volume must be a mapping not a string

Question

Question: Why do I get this error?

ERROR: In file \'./docker-compose.yml\', volume \'mariavolume\' must be a mapping not a string.

Answer 1

try this:

    volumes:
        - maria_volume: /var/lib/mysql
volumes:
    maria_volume: 
        external:
            name: ~/mariadb