Catch additional assertion errors for load_list_of_blocks

lib/ansible/playbook/helpers.py

@@ -34,10 +34,7 @@ def load_list_of_blocks(ds, play, parent_block=None, role=None, task_include=Non
     # we import here to prevent a circular dependency with imports
     from ansible.playbook.block import Block
 
-    try:
     assert isinstance(ds, (list, type(None)))
-    except AssertionError:
-        raise AnsibleParserError("Task list is not a list, invalid format provided: %s" % ds)
 
     block_list = []
     if ds:

lib/ansible/playbook/role/__init__.py

@@ -171,11 +171,17 @@ class Role(Base, Become, Conditional, Taggable):
 
         task_data = self._load_role_yaml('tasks')
         if task_data:
+            try:
                 self._task_blocks = load_list_of_blocks(task_data, play=self._play, role=self, loader=self._loader)
+            except:
+                raise AnsibleParserError("The tasks/main.yml file for role '%s' must contain a list of tasks" % self._role_name , obj=task_data)
 
         handler_data = self._load_role_yaml('handlers')
         if handler_data:
+            try:
                 self._handler_blocks = load_list_of_blocks(handler_data, play=self._play, role=self, use_handlers=True, loader=self._loader)
+            except:
+                raise AnsibleParserError("The handlers/main.yml file for role '%s' must contain a list of tasks" % self._role_name , obj=task_data)
 
         # vars and default vars are regular dictionaries
         self._role_vars  = self._load_role_yaml('vars')