ugh

Author: Luca Forstner

packages/opentelemetry/src/setupEventContextTrace.ts

@@ -19,12 +19,17 @@ export function setupEventContextTrace(client: Client): void {
 
     // If event has already set `trace` context, use that one.
     event.contexts = {
+      ...event.contexts,
       trace: {
+        ...event.contexts?.trace,
+        // We are overriding values here. In theory this is bad and we definitely need to change that in the future.
+        // The reason we need to override here is because in the core sdk we apply span data to the trace context at the time of capturing, and apply the propagation context if there is no span on the scope.
+        // In the OTEL SDK we never have a span on the scope, meaning that the propagation context is applied.
+        // If we now didn't overwrite the trace context here we would end up with the values of the propagation context instead but we want the data from the span.
         trace_id: spanContext.traceId,
         span_id: spanContext.spanId,
         parent_span_id: spanHasParentId(span) ? span.parentSpanId : undefined,
       },
-      ...event.contexts,
     };
 
     return event;