Comment ajouter un module Python à un conteneur docker?

J'ai créé un projet Boilerplate à partir du modèle de projet Divio Django: ( Python 3.6, Django CMS, HTML 5 )

Vérification du référentiel renvoie quelques fichiers, parmi lesquels un docker-compose et un dockerfile.

Docker-compose:

mzh@ale $ docker run -it --rm divio/base:4.14-py3.6-slim-stretch /bin/bash
root@5d65902b34a4:/app# python
Python 3.6.8 (default, Mar 27 2019, 08:53:45) 
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import aldryn_apphooks_config
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'aldryn_apphooks_config'

Donc, localement, j'essaye de lancer

Starting ale_db_1 ... done
/app/addons/aldryn-django/aldryn_config.py:137: RuntimeWarning: no cache configured. Falling back to CACHE_URL=locmem://
  RuntimeWarning,
/app/addons/aldryn-django/aldryn_config.py:137: RuntimeWarning: no cache configured. Falling back to CACHE_URL=locmem://
  RuntimeWarning,
Unhandled exception in thread started by <function check_errors.<locals>.wrapper at 0x7f42a18c4950>
Traceback (most recent call last):
  File "/virtualenv/lib/python3.6/site-packages/django/utils/autoreload.py", line 228, in wrapper
    fn(*args, **kwargs)
  File "/virtualenv/lib/python3.6/site-packages/django/core/management/commands/runserver.py", line 116, in inner_run
    autoreload.raise_last_exception()
  File "/virtualenv/lib/python3.6/site-packages/django/utils/autoreload.py", line 251, in raise_last_exception
    six.reraise(*_exception)
  File "/virtualenv/lib/python3.6/site-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/virtualenv/lib/python3.6/site-packages/django/utils/autoreload.py", line 228, in wrapper
    fn(*args, **kwargs)
  File "/virtualenv/lib/python3.6/site-packages/django/__init__.py", line 27, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/virtualenv/lib/python3.6/site-packages/django/apps/registry.py", line 85, in populate
    app_config = AppConfig.create(entry)
  File "/virtualenv/lib/python3.6/site-packages/django/apps/config.py", line 94, in create
    module = import_module(entry)
  File "/virtualenv/lib/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 994, in _gcd_import
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 953, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'aldryn_apphooks_config'

pour démarrer une instance de CMS Django locale. Cependant, je rencontre l'erreur suivante:

docker-compose run web

Des idées?

Je peux reproduire l'erreur lors du démarrage interactif du conteneur:

version: "2"

services:
  web:
    build: "."
    links:
      - "db:postgres"
    ports:
      - "8000:80"
    volumes:
      - ".:/app:rw"
      - "./data:/data:rw"
    command: python manage.py runserver 0.0.0.0:80
    env_file: .env-local

  db:
    image: postgres:9.6-alpine
    environment:
      POSTGRES_DB: "db"
    volumes:
      - ".:/app:rw"