optuna - assert version is not N

两台服务器，optuna 版本 2.10.1，一台服务器正常运行，一台服务器报错 assert version is not None。
查看源码【optuna.storages._rdb.storage — Optuna 2.10.1 documentation】发现，context.get_current_revision() 提取当前版本为 None 导致。

def get_current_version(self) -> str:
    context = alembic.migration.MigrationContext.configure(self.engine.connect())
    version = context.get_current_revision()
    assert version is not None

    return version

接下来观察一下 optuna 的依赖库版本。安装 pipdeptree，打印 optuna 的依赖结构。

pip install pipdeptree -i https://pypi.douban.com/simple

pipdeptree -p optuna

optuna==2.10.1
  - alembic [required: Any, installed: 1.7.7]
    - importlib-metadata [required: Any, installed: 4.8.3]
      - typing-extensions [required: >=3.6.4, installed: 4.1.1]
      - zipp [required: >=0.5, installed: 3.6.0]
    - importlib-resources [required: Any, installed: 5.4.0]
      - zipp [required: >=3.1.0, installed: 3.6.0]
    - Mako [required: Any, installed: 1.1.6]
      - MarkupSafe [required: >=0.9.2, installed: 2.0.1]
    - SQLAlchemy [required: >=1.3.0, installed: 1.4.45]
      - greenlet [required: !=0.4.17, installed: 2.0.1]
      - importlib-metadata [required: Any, installed: 4.8.3]
        - typing-extensions [required: >=3.6.4, installed: 4.1.1]
        - zipp [required: >=0.5, installed: 3.6.0]
  - cliff [required: Any, installed: 3.10.1]
    - autopage [required: >=0.4.0, installed: 0.5.1]
    - cmd2 [required: >=1.0.0, installed: 2.4.2]
      - attrs [required: >=16.3.0, installed: 22.2.0]
      - importlib-metadata [required: >=1.6.0, installed: 4.8.3]
        - typing-extensions [required: >=3.6.4, installed: 4.1.1]
        - zipp [required: >=0.5, installed: 3.6.0]
      - pyperclip [required: >=1.6, installed: 1.8.2]
      - typing-extensions [required: Any, installed: 4.1.1]
      - wcwidth [required: >=0.1.7, installed: 0.2.5]
    - pbr [required: >=2.0.0,!=2.1.0, installed: 5.11.0]
    - PrettyTable [required: >=0.7.2, installed: 2.5.0]
      - importlib-metadata [required: Any, installed: 4.8.3]
        - typing-extensions [required: >=3.6.4, installed: 4.1.1]
        - zipp [required: >=0.5, installed: 3.6.0]
      - wcwidth [required: Any, installed: 0.2.5]
    - pyparsing [required: >=2.1.0, installed: 3.0.9]
    - PyYAML [required: >=3.12, installed: 6.0]
    - stevedore [required: >=2.0.1, installed: 3.5.2]
      - importlib-metadata [required: >=1.7.0, installed: 4.8.3]
        - typing-extensions [required: >=3.6.4, installed: 4.1.1]
        - zipp [required: >=0.5, installed: 3.6.0]
      - pbr [required: >=2.0.0,!=2.1.0, installed: 5.11.0]
  - cmaes [required: >=0.8.2, installed: 0.9.0]
    - numpy [required: Any, installed: 1.19.5]
  - colorlog [required: Any, installed: 6.7.0]
  - numpy [required: Any, installed: 1.19.5]
  - packaging [required: >=20.0, installed: 21.3]
    - pyparsing [required: >=2.0.2,!=3.0.5, installed: 3.0.9]
  - PyYAML [required: Any, installed: 6.0]
  - scipy [required: !=1.4.0, installed: 1.5.4]
    - numpy [required: >=1.14.5, installed: 1.19.5]
  - sqlalchemy [required: >=1.1.0, installed: 2.0.3]
    - greenlet [required: !=0.4.17, installed: 2.0.1]
    - importlib-metadata [required: Any, installed: 4.8.3]
      - typing-extensions [required: >=3.6.4, installed: 4.1.1]
      - zipp [required: >=0.5, installed: 3.6.0]
  - tqdm [required: Any, installed: 4.64.1]
    - importlib-resources [required: Any, installed: 5.4.0]
      - zipp [required: >=3.1.0, installed: 3.6.0]

发现报错服务器环境的 sqlalchemy==2.0.3，无报错服务器环境的 sqlalchemy==1.4.45，将 sqlalchemy 从 2.0.3 将至 1.4.45 后，assert version is not None 解决。

optuna.storages._rdb.storage — Optuna 2.10.1 documentation

AssertionError thrown when creating study, but only on some machines · Issue #4392 · optuna/optuna (github.com)