Surpressing multi-threaded process warning from rosbag2 flake8.

[fujitatomoya]

Description

• before

root@tomoyafujita-B760M-Pro-RS-D4:~/ros2_ws/colcon_ws# colcon test --event-handlers console_direct+ --packages-select ros2bag
Starting >>> ros2bag
============================= test session starts ==============================
platform linux -- Python 3.12.3, pytest-7.4.4, pluggy-1.4.0
cachedir: /root/ros2_ws/colcon_ws/build/ros2bag/.pytest_cache
rootdir: /root/ros2_ws/colcon_ws/src/ros2/rosbag2/ros2bag
configfile: pytest.ini
plugins: launch-testing-ros-0.29.5, launch-testing-3.9.6, ament-mypy-0.20.3, ament-xmllint-0.20.3, ament-copyright-0.20.3, ament-pep257-0.20.3, ament-flake8-0.20.3, ament-lint-0.20.3, anyio-4.11.0, None-None, timeout-2.2.0, cov-4.1.0, rerunfailures-12.0, mock-3.12.0, colcon-core-0.20.1
collecting ...
collected 41 items

test/test_api.py .......                                                 [ 17%]
test/test_burst.py .                                                     [ 19%]
test/test_cli_extension.py .                                             [ 21%]
test/test_copyright.py .                                                 [ 24%]
test/test_flake8.py .                                                    [ 26%]
test/test_info.py .                                                      [ 29%]
test/test_pep257.py .                                                    [ 31%]
test/test_play_qos_profiles.py .                                         [ 34%]
test/test_record.py .                                                    [ 36%]
test/test_record_qos_profiles.py .                                       [ 39%]
test/test_record_with_compression_thread_priority.py .                   [ 41%]
test/test_recorder_args_parser.py .......................                [ 97%]
test/test_xmllint.py .                                                   [100%]

=============================== warnings summary ===============================
test/test_flake8.py: 28 warnings
  Warning: This process (pid=34066) is multi-threaded, use of fork() may lead to deadlocks in the child.

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
----- generated xml file: /root/ros2_ws/colcon_ws/build/ros2bag/pytest.xml -----
======================= 41 passed, 28 warnings in 10.10s =======================
--- stderr: ros2bag

=============================== warnings summary ===============================
test/test_flake8.py: 28 warnings
  Warning: This process (pid=34066) is multi-threaded, use of fork() may lead to deadlocks in the child.

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
---
Finished <<< ros2bag [10.7s]

Summary: 1 package finished [11.5s]
  1 package had stderr output: ros2bag

• after

root@tomoyafujita-B760M-Pro-RS-D4:~/ros2_ws/colcon_ws# colcon test --event-handlers console_direct+ --packages-select ros2bag
Starting >>> ros2bag
============================= test session starts ==============================
platform linux -- Python 3.12.3, pytest-7.4.4, pluggy-1.4.0
cachedir: /root/ros2_ws/colcon_ws/build/ros2bag/.pytest_cache
rootdir: /root/ros2_ws/colcon_ws/src/ros2/rosbag2/ros2bag
configfile: pytest.ini
plugins: launch-testing-ros-0.29.5, launch-testing-3.9.6, ament-mypy-0.20.3, ament-xmllint-0.20.3, ament-copyright-0.20.3, ament-pep257-0.20.3, ament-flake8-0.20.3, ament-lint-0.20.3, anyio-4.11.0, None-None, timeout-2.2.0, cov-4.1.0, rerunfailures-12.0, mock-3.12.0, colcon-core-0.20.1
timeout: 900.0s
timeout method: thread
timeout func_only: False
collecting ...
collected 41 items

test/test_api.py .......                                                 [ 17%]
test/test_burst.py .                                                     [ 19%]
test/test_cli_extension.py .                                             [ 21%]
test/test_copyright.py .                                                 [ 24%]
test/test_flake8.py .                                                    [ 26%]
test/test_info.py .                                                      [ 29%]
test/test_pep257.py .                                                    [ 31%]
test/test_play_qos_profiles.py .                                         [ 34%]
test/test_record.py .                                                    [ 36%]
test/test_record_qos_profiles.py .                                       [ 39%]
test/test_record_with_compression_thread_priority.py .                   [ 41%]
test/test_recorder_args_parser.py .......................                [ 97%]
test/test_xmllint.py .                                                   [100%]

----- generated xml file: /root/ros2_ws/colcon_ws/build/ros2bag/pytest.xml -----
============================== 41 passed in 9.56s ==============================
Finished <<< ros2bag [10.2s]

Summary: 1 package finished [11.0s]

Fixes # (issue)

Is this user-facing behavior change?

No

Did you use Generative AI?

No

Additional Information

https://github.com/ros2/sros2/blob/rolling/sros2/pytest.ini, we have done the same thing to sros2.

[Copilot]

Pull request overview

This PR updates ros2bag’s pytest configuration to eliminate noisy warnings during the flake8 test run (notably the “multi-threaded, use of fork() may lead to deadlocks” warning observed under Python 3.12/Ubuntu 22.04).

Changes:

• Adds pytest-timeout configuration (900s per-test timeout, thread-based timeout method).
• Converts filterwarnings to a multi-line list and adds a filter to suppress the fork-in-multithreaded-process warning.

---

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[fujitatomoya]

Pulls: #2329
Gist: https://gist.githubusercontent.com/fujitatomoya/9a57d81c73dcf9882acc9db4d4407b60/raw/c201a3b28592e728866591cedbc97d4263150fa2/ros2.repos
BUILD args: --packages-above-and-dependencies ros2bag
TEST args: --packages-above ros2bag
ROS Distro: rolling
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/18193

• Linux
• Linux-aarch64
• Linux-rhel
• Windows