Hint users when weight update timeouts (#6570)

python/sglang/srt/model_executor/expert_location_updater.py

@@ -338,8 +338,14 @@ def update_expert_weights_single_layer(
             return
 
         reqs = torch.distributed.batch_isend_irecv(p2p_ops)
+        try:
             for req in reqs:
-            req.wait()
+                req.wait(timeout=30)
+        except RuntimeError:
+            logger.error(
+                f"Context: {rank=} {old_physical_to_logical_map=} {new_physical_to_logical_map=} {num_local_physical_experts=} {num_gpu_per_node=}"
+            )
+            raise
 
     def _execute_buffer2weight_copies(buffer2weight_copy_infos):
         for (