Parent IDs are null for spawned spans with gevent auto-instrumentation

[CagriYonca]

Describe your environment

OS: MacOS
Python version: 3.12.4
telemetry.sdk.version: 1.28.2
telemetry.auto.version: 0.49b2

What happened?

I'm trying to use auto-instrument with gevent, but the parent ids are null for spawned spans. Am I missing anything or do you have any suggestion?

Steps to Reproduce

Server Code

from gevent import monkey

monkey.patch_all()

from flask import Flask, request

app = Flask(__name__)


@app.route("/server_request")
def server_request():
    print(request.args.get("param"))
    return "served"


if __name__ == "__main__":
    app.run(port=8082)

• Run with:
  opentelemetry-instrument --traces_exporter console --metrics_exporter none python server_automatic.py

Client Code

import gevent

from sys import argv

from requests import get

from opentelemetry import trace
from opentelemetry.propagate import inject
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import (
    BatchSpanProcessor,
    ConsoleSpanExporter,
)
from opentelemetry.instrumentation.requests import RequestsInstrumentor

RequestsInstrumentor().instrument()

trace.set_tracer_provider(TracerProvider())
tracer = trace.get_tracer_provider().get_tracer(__name__)

trace.get_tracer_provider().add_span_processor(
    BatchSpanProcessor(ConsoleSpanExporter())
)

assert len(argv) == 2


def make_http_call(n=None):
    headers = {}
    inject(headers)
    return get(
        "http://localhost:8082/server_request",
        params={"param": argv[1]},
        headers=headers,
    )


def spawn_calls():
    with tracer.start_as_current_span("spawn_calls"):
        jobs = []
        jobs.append(gevent.spawn(make_http_call))
        jobs.append(gevent.spawn(make_http_call))
        jobs.append(gevent.spawn(make_http_call))
        gevent.joinall(jobs, timeout=2)


def launch_gevent_chain():
    with tracer.start_as_current_span("test"):
        gevent.spawn(spawn_calls).join()


gevent.spawn(launch_gevent_chain)

gevent.sleep(2)

• Run with:
  python client.py otel-flask-gevent-testing

Expected Result

I was expecting to see spawn_calls's span id as spawned spans' pids.

Actual Result

Parent IDs in the results are null

Additional context

No response

Would you like to implement a fix?

None