when the Unmarshaler parsing value by fillSliceFromString, if the val… (#3927)

Co-authored-by: danahan <danahan@tencent.com>

core/mapping/unmarshaler.go

@@ -223,11 +223,11 @@ func (u *Unmarshaler) fillSliceFromString(fieldType reflect.Type, value reflect.
 	switch v := mapValue.(type) {
 	case fmt.Stringer:
 		if err := jsonx.UnmarshalFromString(v.String(), &slice); err != nil {
-			return err
+			return fmt.Errorf("fullName: `%s`, error: `%w`", fullName, err)
 		}
 	case string:
 		if err := jsonx.UnmarshalFromString(v, &slice); err != nil {
-			return err
+			return fmt.Errorf("fullName: `%s`, error: `%w`", fullName, err)
 		}
 	default:
 		return errUnsupportedType