better leader support in extra

src/rougail/template/base.py

@@ -448,7 +448,7 @@ class RougailBaseTemplate:
                                                        await suboption.option.name(),
                                                        await suboption.option.path(),
                                                        )
-                    variables[leadership_name] = leader
+                    variables[leadership_name] = RougailExtra({leader_name: leader})
                 else:
                     if is_service_namespace == 'root':
                         new_is_service_namespace = 'service_name'

src/rougail/template/engine/creole.py

@@ -118,7 +118,7 @@ def process(filename: str,
                                            )
         data = str(cheetah_template)
     except NotFound as err:  # pragma: no cover
-        varname = err.args[0][13:-1]
+        varname = err.args[0][13:].split(' ', 1)[0][:-1]
         if filename:
             msg = f"Error: unknown variable used in template {filename} to {destfilename}: {varname}"
         else: