Function pa_capture_session_open 

pub(crate) fn pa_capture_session_open(
    inner: &Inner,
    spec: &Spec,
    device: Option<&str>,
    attr: &BufferAttr,
    adjust_latency: bool,
    device_was_present: bool,
) -> Result<PaCaptureSession, SessionOpenError>

Open a capture session: mainloop + context + record stream driven to Ready on the bounded pump, honoring stop_pending at every turn. A NAMED device is validated by an introspect probe on every call (an async connect_record would not fail synchronously on a bad name, and on reconnect this is also what notices the device reappearing after an outage). device_was_present distinguishes initial bring-up from reconnect: a named device missing at startup is probably a misconfiguration, so it is reported as DeviceNotFound and the caller spends only a short window on it; the same device vanishing mid-run (PulseAudio/PipeWire restart kills every source) is transient and must be retried or audio never comes back.