NoneType object has no attribute configure

[markparonyan]

Describe the bug
The error:

ERROR - asyncio - Task exception was never retrieved
future: <Task finished name='Task-4' coro=<run_async_migrations() done, defined at /app/migrations/env.py:72> exception=AttributeError("'NoneType' object has no attribute 'configure'")>

This is how I run alembic:

        alembic_cfg = Config(alembic_config_path)
        command.upgrade(alembic_cfg, "head")

This is my env.py

from sqlalchemy import pool
from sqlalchemy.engine import Connection
from sqlalchemy.ext.asyncio import async_engine_from_config

from alembic import context

# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config

# Interpret the config file for Python logging.
# This line sets up loggers basically.
#if config.config_file_name is not None:
#    fileConfig(config.config_file_name)

# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata
from db.base import Base

target_metadata = Base.metadata

# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.


def run_migrations_offline() -> None:
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    url = config.get_main_option("sqlalchemy.url")
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )

    with context.begin_transaction():
        context.run_migrations()


def do_run_migrations(connection: Connection) -> None:
    context.configure(connection=connection, target_metadata=target_metadata)

    with context.begin_transaction():
        context.run_migrations()


async def run_async_migrations() -> None:
    """In this scenario we need to create an Engine
    and associate a connection with the context.

    """

    connectable = async_engine_from_config(
        config.get_section(config.config_ini_section, {}),
        prefix="sqlalchemy.",
        poolclass=pool.NullPool,
    )

    async with connectable.connect() as connection:
        await connection.run_sync(do_run_migrations)

    await connectable.dispose()


def run_migrations_online() -> None:
    """Run migrations in 'online' mode."""
    # https://github.com/sqlalchemy/alembic/discussions/1515#discussioncomment-10246673
    try:
        # use preexisting event loop if already in async context
        asyncio.create_task(run_async_migrations())
    except RuntimeError:
        asyncio.run(run_async_migrations())


if context.is_offline_mode():
    run_migrations_offline()
else:
    run_migrations_online()

Versions.

• OS: archlinux
• Python: 3.11
• alembic==1.15.2
• SQLAlchemy==2.0.40
• Database: postgresql

[markparonyan]

@zzzeek please take a look, same issue was here #862

[CaselIT]

Hi,

have you tried the same solution? Meaning ensure that you are not running alembic commands while importing the module.
Easiest way of checking for it is to remove the from db.base import Base