3.0.3 xcom_pull inconsistent content returned when using file storage

[puzzle9]

Apache Airflow version

3.0.3

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

3.0.2

What happened?

In version 3.0.2, the returned content is
In version 3.0.3, the returned path is

normal

error

What you think should happen instead?

No response

How to reproduce

from datetime import datetime
from airflow import DAG
from airflow.decorators import task

with DAG(
        dag_id='dag_test_xcom',
        schedule='@once',
        start_date=datetime(2025, 7, 10),
) as dag:
    @task(do_xcom_push=True)
    def gen_xcom():
        print("data")
        return 'a' * 1024 * 1024


    @task
    def get_xcom(**context):
        datas = context['ti'].xcom_pull(task_ids='gen_xcom')
        print(datas)


    gen_xcom() >> [get_xcom()]

Operating System

Debian GNU/Linux 12 (bookworm)

Versions of Apache Airflow Providers

No response

Deployment

Docker-Compose

Deployment details

No response

Anything else?

No response

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

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

[boring-cyborg]

Thanks for opening your first issue here! Be sure to follow the issue template! If you are willing to raise PR to address this issue please do so, no need to wait for approval.

[jroachgolf84]

Are you using a custom XCom backend? If so, which one?

[puzzle9]

Are you using a custom XCom backend? If so, which one?

xcom_backend = airflow.providers.common.io.xcom.backend.XComObjectStorageBackend
xcom_objectstorage_path = file:///opt/airflow/xcoms
xcom_objectstorage_threshold = 102400

[eladkal]

@amoghrajesh could this regression caused by #51568 ?
That is the only change to xcom_pull I could find between 3.0.2 to 3.0.3

[amoghrajesh]

Thanks for tagging me @eladkal. Let me take a look at this, it is possible that this could've happened as a side effect of #51568

[amoghrajesh]

Added the right milestone too. Thanks for reporting!