fix: allow no user_datas installation (for example to generate doc)

src/rougail/convert.py

@@ -178,7 +178,10 @@ class ParserVariable:
             "structural_commandline.add_extra_options"
         ]
         self.structurals = rougailconfig["step.structural"]
-        self.user_datas = rougailconfig["step.user_data"]
+        try:
+            self.user_datas = rougailconfig["step.user_data"]
+        except:
+            self.user_datas = []
         try:
             self.output = rougailconfig["step.output"]
         except:

src/rougail/object_model.py

@@ -452,7 +452,7 @@ class _VariableCalculation(Calculation):
         )
         if variable and not isinstance(variable, objectspace.variable):
             if isinstance(variable, objectspace.family):
-                msg = f'the variable "{variable.path}" is in fact a family in attribute "{self.attribute_name}" for "{self.path}"'
+                msg = f'a variable "{variable.path}" is needs in attribute "{self.attribute_name}" for "{self.path}" but it\'s a family'
                 raise DictConsistencyError(msg, 47, self.xmlfiles)
             else:
                 msg = f'unknown object "{variable}" in attribute "{self.attribute_name}" for "{self.path}"'

src/rougail/path.py

@@ -74,7 +74,6 @@ class Paths:
     def get_with_dynamic(
         self,
         path: str,
-        #        identifier_path: str,
         current_path: str,
         version: str,
         namespace: str,
@@ -145,9 +144,7 @@ class Paths:
                 if "{{ suffix }}" in path:
                     path = path.replace("{{ suffix }}", "{{ identifier }}")
         elif not path in self._data:
-            current_path = None
-            parent_path = None
-            new_path = current_path
+            new_path = parent_path = current_path = None
             identifiers = []
             for name in path.split("."):
                 if current_path: