Add debug logging for weight loading failures

vllm/patches/deepseek_v4.py

@@ -1565,13 +1565,28 @@ class DeepseekV4Model(nn.Module):
                 else:
                     if is_pp_missing_parameter(name, self):
                         continue
+                    if name not in params_dict:
+                        logger.warning(
+                            "Skipping weight %s (not in model params)", name
+                        )
+                        continue
                     param = params_dict[name]
                     weight_loader = getattr(
                         param, "weight_loader", default_weight_loader
                     )
-                    weight_loader(param, loaded_weight)
-                    loaded_params.add(name)
-                    continue
+                    try:
+                        weight_loader(param, loaded_weight)
+                    except (AssertionError, RuntimeError) as e:
+                        logger.error(
+                            "Failed to load weight %s: param shape=%s, "
+                            "loaded shape=%s, dtype=%s, error=%s",
+                            name,
+                            param.data.shape if hasattr(param, 'data') else '?',
+                            loaded_weight.shape,
+                            loaded_weight.dtype,
+                            e,
+                        )
+                        raise
 
         # Load buffered compressor/indexer scale params.
         # These are NVFP4 quantization scales that need concatenation