[Bug] workflow.wait broken with asyncio.FIRST_COMPLETED and local activities

[andmis]

What are you really trying to do?

Start N local activities, wait for the first one to finish, cancel the others.

Describe the bug

If I start N local activities, then use workflow.wait(tasks, return_when=asyncio.FIRST_COMPLETED), the workflow.wait coro blocks until all of the activities actually finish, instead of returning when the first one finishes. If I use non-local activities, this bug does not happen.

Minimal Reproduction

https://github.com/andmis/snippets/tree/temporal-python-sdk-local-activity-workflow-wait-bug

# Worker output after `python run_workflow.py`
2024-12-09 19:02:30.750775+00:00 (Workflow) Starting, local=False
2024-12-09 19:02:30.750775+00:00 (Workflow) Waiting for first completed activity
2024-12-09 11:02:30.760073 (Activity 0) Running sandbox_activity
2024-12-09 11:02:30.760565 (Activity 1) Running sandbox_activity
2024-12-09 11:02:32.875597 (Activity 1) Exiting sandbox_activity
2024-12-09 19:02:32.891753+00:00 (Workflow) Got first completed activity, cancelling others and exiting
2024-12-09 19:02:32.891753+00:00 (Workflow) Exiting
2024-12-09 11:02:35.328912 (Activity 0) Cancelling sandbox_activity

# Worker output after `python run_workflow.py -l`
2024-12-09 19:03:48.421271+00:00 (Workflow) Starting, local=True
2024-12-09 19:03:48.421271+00:00 (Workflow) Waiting for first completed activity
2024-12-09 11:03:48.425911 (Activity 0) Running sandbox_activity
2024-12-09 11:03:48.426165 (Activity 1) Running sandbox_activity
2024-12-09 11:03:49.817020 (Activity 1) Exiting sandbox_activity
2024-12-09 11:03:56.397142 (Activity 0) Exiting sandbox_activity
2024-12-09 19:03:56.394210+00:00 (Workflow) Got first completed activity, cancelling others and exiting
2024-12-09 19:03:56.394210+00:00 (Workflow) Exiting
# Note the timestamps

Environment/Versions

• OS and processor: macOS, M1
• Temporal version: 1.1.2
• Python SDK version: 1.8.0
• Are you using Docker or Kubernetes or building Temporal from source? No

Additional context

[cretz]

Thanks! We will investigate.