I am getting segfaults when running gunicorn 20.1.0 and setproctitle 1.3.0. My environment is Python3.10/macOS 12.5 MacBookPro M1. To reproduce create a file named test.py with the following contents:

def app(environ, start_response):
    """Simplest possible application object"""
    data = b'Hello, World!\n'
    status = '200 OK'
    response_headers = [
        ('Content-type', 'text/plain'),
        ('Content-Length', str(len(data)))
    ]
    start_response(status, response_headers)
    return iter([data])

Install gunicorn==20.1.0 setproctitle==1.3.0. Then execute the command:

gunicorn test:app

I receive the following output:

[2022-08-03 12:12:04 -0700] [99378] [INFO] Starting gunicorn 20.1.0
[2022-08-03 12:12:04 -0700] [99378] [INFO] Listening at: http://127.0.0.1:8000 (99378)
[2022-08-03 12:12:04 -0700] [99378] [INFO] Using worker: sync
[2022-08-03 12:12:06 -0700] [99378] [WARNING] Worker with pid 99380 was terminated due to signal 11
[2022-08-03 12:12:07 -0700] [99378] [WARNING] Worker with pid 99382 was terminated due to signal 11

If I downgrade the version of setproctitle to 1.2.3, there is no segfault. I did some investigation locally to try to isolate which commit is the cause of this and I believe that c993231 is the commit where this was introduced. If I install the package using python setup.py install for that commit, the segfault occurs. If I install 87378de (commit immediately preceding it on master), the error does not occur.

I can't get the error to reproduce as a standalone script (just calling setproctittle()), so I am not clear on why the error only occurs when running with gunicorn.