Span.record_exception must also set the span status to error

src/core/span.ml

@@ -103,17 +103,21 @@ let add_event' self ev : unit =
 let record_exception (self : t) (exn : exn) (bt : Printexc.raw_backtrace) : unit
     =
   if is_not_dummy self then (
+    let exn_msg = Printexc.to_string exn in
     let ev =
       Event.make "exception"
         ~attrs:
           [
-            "exception.message", `String (Printexc.to_string exn);
+            "exception.message", `String exn_msg;
             "exception.type", `String (Printexc.exn_slot_name exn);
             ( "exception.stacktrace",
               `String (Printexc.raw_backtrace_to_string bt) );
           ]
     in
-    add_event self ev
+    add_event self ev;
+
+    let status = make_status ~code:Status_code_error ~message:exn_msg () in
+    span_set_status self status
   )
 
 let add_attrs (self : t) (attrs : Key_value.t list) : unit =

src/core/span.mli

@@ -94,6 +94,8 @@ val add_event' : t -> (unit -> Event.t) -> unit
     it if there is an instrumentation backend. *)
 
 val record_exception : t -> exn -> Printexc.raw_backtrace -> unit
+(** Record an exception occurring inside the span. This creates a span event
+    {b and} also sets the span status to error. *)
 
 val add_links : t -> Span_link.t list -> unit
 

src/lib/trace_provider.ml

@@ -94,12 +94,7 @@ let with_thunk_and_finally (self : Tracer.t) ?(force_new_trace_id = false)
     | None ->
       (match res with
       | Ok () -> ()
-      | Error (e, bt) ->
+      | Error (e, bt) -> Span.record_exception span e bt));
-        Span.record_exception span e bt;
-        let status =
-          make_status ~code:Status_code_error ~message:(Printexc.to_string e) ()
-        in
-        Span.set_status span status));
 
     Emitter.emit self.emit [ span ]
   in