Cannot create a new span, it keeps reusing parent span

[equal-l2]

I want to create a new span as a child of an external span, but it fails.
Instead of a new span, it keeps reusing the parent span.

Code:

fn fn_rs(millis: u64, context_carrier: HashMap<String, String>) -> String {
    println!("context_carrier: {:?}", context_carrier);

    let remote_context = opentelemetry_sdk::propagation::TraceContextPropagator::new()
        .extract(&context_carrier);
    println!("remote_context span: {:?}", remote_context.span());

    let _guard = remote_context.attach();
    println!("current context span: {:?}", Context::current().span());

    let tracer = opentelemetry::global::tracer("arbitrary-random-name");
    {
        let mut _span = tracer.start("sleep_rs_1");
        println!("sleep_rs_1: {:?}", _span.span_context());
        sleep(std::time::Duration::from_millis(millis));
    }
    {
        let _span = tracer.start("sleep_rs_2");
        println!("sleep_rs_2: {:?}", _span.span_context());
        sleep(std::time::Duration::from_millis(millis));
    }

    "Rust: OK".to_owned()
}

Output:

context_carrier: {"traceparent": "00-97b39a8bb84f3d516d0f09ab73af1b60-d01a6d712b21bb62-01"}
remote_context span: SpanRef(SynchronizedSpan { span_context: SpanContext { trace_id: 97b39a8bb84f3d516d0f09ab73af1b60, span_id: d01a6d712b21bb62, trace_flags: TraceFlags(1), is_remote: true, trace_state: TraceState(None) }, inner: None })
current context span: SpanRef(SynchronizedSpan { span_context: SpanContext { trace_id: 97b39a8bb84f3d516d0f09ab73af1b60, span_id: d01a6d712b21bb62, trace_flags: TraceFlags(1), is_remote: true, trace_state: TraceState(None) }, inner: None })
sleep_rs_1: SpanContext { trace_id: 97b39a8bb84f3d516d0f09ab73af1b60, span_id: d01a6d712b21bb62, trace_flags: TraceFlags(1), is_remote: true, trace_state: TraceState(None) }
sleep_rs_2: SpanContext { trace_id: 97b39a8bb84f3d516d0f09ab73af1b60, span_id: d01a6d712b21bb62, trace_flags: TraceFlags(1), is_remote: true, trace_state: TraceState(None) }

[equal-l2]

The equivalent in Python is working well.

Code:

def fn_py(millis: int, context_carrier: dict[str, str]):
    print("context carrier:", context_carrier)

    remote_context = extract(context_carrier)
    print("remote context:", remote_context)

    attach(remote_context)
    print("current context:", get_current())

    with tracer.start_as_current_span("sleep_py_1") as span:
        print("sleep_py_1:", span)
        time.sleep(millis / 1000)
    with tracer.start_as_current_span("sleep_py_2") as span:
        print("sleep_py_2:", span)
        time.sleep(millis / 1000)

    return "Python: OK"

Output (note sleep_py_1 and sleep_py_2 are distinct from their parent, and have distinct span ids for each):

context carrier: {'traceparent': '00-a5f8552cfe0dc413842e1b0e3ad99b96-3c884bac4b54d22c-01'}
remote context: {'current-span-b769e3e3-b5b6-47cc-907f-aa3a52868846': NonRecordingSpan(SpanContext(trace_id=0xa5f8552cfe0dc413842e1b0e3ad99b96, span_id=0x3c884bac4b54d22c, trace_flags=0x01, trace_state=[], is_remote=True))}
current context: {'current-span-b769e3e3-b5b6-47cc-907f-aa3a52868846': NonRecordingSpan(SpanContext(trace_id=0xa5f8552cfe0dc413842e1b0e3ad99b96, span_id=0x3c884bac4b54d22c, trace_flags=0x01, trace_state=[], is_remote=True))}
sleep_py_1: _Span(name="sleep_py_1", context=SpanContext(trace_id=0xa5f8552cfe0dc413842e1b0e3ad99b96, span_id=0x6bc52b62ae94ee68, trace_flags=0x01, trace_state=[], is_remote=False))
sleep_py_2: _Span(name="sleep_py_2", context=SpanContext(trace_id=0xa5f8552cfe0dc413842e1b0e3ad99b96, span_id=0x7a2f89defc1592ae, trace_flags=0x01, trace_state=[], is_remote=False))

[equal-l2]

Nevermind, I missed a breaking change and failed to set TracerProvider, which made tracer to a instance of NoopTracer.

Breaking The methods OtlpTracePipeline::install_simple() and OtlpTracePipeline::install_batch() would now return TracerProvider instead of Tracer. These methods would also no longer set the global tracer provider. It would now be the responsibility of users to set it by calling global::set_tracer_provider(tracer_provider.clone());. Refer to the basic-otlp and basic-otlp-http examples on how to initialize OTLP Trace Exporter.
https://github.com/open-telemetry/opentelemetry-rust/blob/main/opentelemetry-otlp/CHANGELOG.md#v0170