[Bug] PYTHON_ENABLE_OPENTELEMETRY=true crashes every async invocation (NoneType.extract) on v2 runtime, Python 3.13

[lynochka]

Expected Behavior

With host.json telemetryMode: OpenTelemetry and app setting PYTHON_ENABLE_OPENTELEMETRY=true, async functions should invoke normally (the worker should either initialize the OpenTelemetry trace-context propagator or no-op safely)

Actual Behavior

Every async invocation returns HTTP 500. In v2 worker_init (runtimes/v2/azure_functions_runtime/handle_event.py), PYTHON_ENABLE_OPENTELEMETRY=true only calls otel_manager.set_otel_libs_available(True) and never calls update_opentelemetry_status() (unlike the PYTHON_APPLICATIONINSIGHTS_ENABLE_TELEMETRY path). The propagator stays None, so per-invocation context activation crashes:

 AttributeError: 'NoneType' object has no attribute 'extract'
   File ".../azure_functions_runtime/otel.py", line 112, in configure_opentelemetry
     ctx = otel_manager.get_trace_context_propagator().extract(carrier)

Removing the setting makes the app healthy. Appears to be the crash manifestation of #1870.

Steps to Reproduce

1. Deploy a Python 3.13 Flex Consumption function app with an async HTTP trigger.
2. host.json: { "version": "2.0", "telemetryMode": "OpenTelemetry" }.
3. Add app setting PYTHON_ENABLE_OPENTELEMETRY=true.
4. Call any async function -> HTTP 500 with the AttributeError above.
5. Remove PYTHON_ENABLE_OPENTELEMETRY -> healthy.

Relevant code being tried

host.json: `{ "version": "2.0", "telemetryMode": "OpenTelemetry" }`

App setting:  PYTHON_ENABLE_OPENTELEMETRY=true 
(App also calls  azure.monitor.opentelemetry.configure_azure_monitor(...) at startup; removing that call does not change the crash.)

Relevant log output

AttributeError: 'NoneType' object has no attribute 'extract'
   File ".../azure_functions_runtime/otel.py", line ~112, in configure_opentelemetry
     ctx = otel_manager.get_trace_context_propagator().extract(carrier)

requirements.txt file

azure-functions
azure-functions-durable
azure-monitor-opentelemetry

Where are you facing this problem?

Production Environment (explain below)

Function app name

No response

Additional Information

Hosting: Azure Functions Flex Consumption (FC1), Python 3.13, v2 azure_functions_runtime.

Related:
#1870 (worker-side auto-init gap),
#1626 (late context propagation).

Suggested fix: call  update_opentelemetry_status()  in the  PYTHON_ENABLE_OPENTELEMETRY  branch of worker_init  (symmetric to the App Insights path), and/or add a  None  guard in  configure_opentelemetry() .

[Oberon00]

This seems to happen also on synchronous, i.e. it seems not specific to async only invocations.

Also IIUC there is no way to manually initialize this extractor, as it seems to be something internal to the Azure worker with no (documented?) way to set it up, even manually configuring OTel would not solve it IIUC. So AFAICT PYTHON_ENABLE_OPENTELEMETRY is really unusable at the moment?