Fig apparently not using volume_from on mysql service

Question

I'm trying to setup a very simple setup of a mysql database using a data-container as repository using Fig.sh and Docker.

The code below is self-explanatory:

web:
  build: .
  command: php -S 0.0.0.0:8000 -t /code
  ports:
    - "8000:8000"
  links:
    - db
  volumes:
    - .:/code
dbdata:
  image: busybox
  command: /bin/sh
  volumes:
    - /var/lib/mysql
db:
  image: mysql
  volumes_from:
    - dbdata
  environment:
    MYSQL_DATABASE: database
    MYSQL_ROOT_PASSWORD: rootpasswd

For some reason, if I run a command fig run --rm dbdata /bin/sh and then I cd into the directory /var/lib/mysql. The folder is empty. If I run fig run --rm db /bin/sh and cd into /var/lib/mysql the database is being created there.

What am I doing wrong here? And taking advantage of the question, is this the correct setup or I should let the data inside the mysql container?

Thanks.