mypy: Value of type "XComArg" is not indexable

[hterik]

Apache Airflow version

2.9.1

If "Other Airflow 2 version" selected, which one?

No response

What happened?

1. Try to make a DAG following the example on https://airflow.apache.org/docs/apache-airflow/2.9.1/core-concepts/taskflow.html#taskflow
2. Run mypy in strict mode on this DAG (mypy version 1.10.0)
3. mypy fails with error

   example.py:20 error: Value of type "XComArg" is not indexable  [index]
   example.py:21 error: Value of type "XComArg" is not indexable  [index]

What you think should happen instead?

Mypy should allow usage of XComArgs using multiple_outputs=True

How to reproduce

See above

Operating System

Ubuntu 24.04

Versions of Apache Airflow Providers

No response

Deployment

Other Docker-based deployment

Deployment details

No response

Anything else?

Possibly related to https://github.com/apache/airflow/issues/39514

Are you willing to submit PR?

• [ ] Yes I am willing to submit a PR!

Code of Conduct

• [X] I agree to follow this project's Code of Conduct

[RNHTTR]

Can you try with mypy 1.9.0, which is what Airflow uses and is defined in constraints

[hterik]

Same error with mypy 1.9.0

[github-actions[bot]]

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