Improve error reporting by adding file locations to exceptions

launch/launch/actions/include_launch_description.py

@@ -18,6 +18,7 @@
 from typing import Iterable, Sequence
 from typing import List
 from typing import Optional
+from typing import Text
 from typing import Tuple
 from typing import Union
 
@@ -160,8 +161,13 @@ def execute(self, context: LaunchContext) -> List[LaunchDescriptionEntity]:
             perform_substitutions(context, normalize_to_list_of_substitutions(arg_name))
             for arg_name, arg_value in self.launch_arguments
         ]
-        declared_launch_arguments = (
-            launch_description.get_launch_arguments_with_include_launch_description_actions())
+        try:
+            declared_launch_arguments = (
+                launch_description.get_launch_arguments_with_include_launch_description_actions())
+        except Exception as exc:
+            if hasattr(exc, 'add_note'):
+                exc.add_note(f'while executing {self.describe()}')
+            raise
         for argument, ild_actions in declared_launch_arguments:
             if argument._conditionally_included or argument.default_value is not None:
                 continue
@@ -183,3 +189,7 @@ def execute(self, context: LaunchContext) -> List[LaunchDescriptionEntity]:
 
         # Set launch arguments as launch configurations and then include the launch description.
         return [*set_launch_configuration_actions, launch_description]
+
+    def __repr__(self) -> Text:
+        """Return a description of this IncludeLaunchDescription as a string."""
+        return f'IncludeLaunchDescription({self.__launch_description_source.location})'

launch/launch/launch_description.py

@@ -148,10 +148,15 @@ def process_entities(entities, *, _conditional_inclusion, nested_ild_actions=Non
                         if next_nested_ild_actions is None:
                             next_nested_ild_actions = []
                         next_nested_ild_actions.append(entity)
-                    process_entities(
-                        entity.describe_sub_entities(),
-                        _conditional_inclusion=False,
-                        nested_ild_actions=next_nested_ild_actions)
+                    try:
+                        process_entities(
+                            entity.describe_sub_entities(),
+                            _conditional_inclusion=False,
+                            nested_ild_actions=next_nested_ild_actions)
+                    except Exception as e:
+                        if hasattr(e, 'add_note'):
+                            e.add_note(f'processing sub-entities of entity: {entity}')
+                        raise
                     for conditional_sub_entity in entity.describe_conditional_sub_entities():
                         process_entities(
                             conditional_sub_entity[1],

launch/launch/substitutions/path_join_substitution.py

@@ -36,7 +36,7 @@ def substitutions(self) -> Iterable[Substitution]:
         """Getter for variable_name."""
         return self.__substitutions
 
-    def describe(self) -> Text:
+    def __repr__(self) -> Text:
         """Return a description of this substitution as a string."""
         return f"PathJoin('{' + '.join([s.describe() for s in self.substitutions])}')"