yaml inventory: Better error reporting on typo. fixes (#31118)

lib/ansible/plugins/inventory/__init__.py

@@ -19,12 +19,13 @@
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
+from collections import MutableMapping
 import hashlib
 import os
 import re
 import string
 
-from ansible.errors import AnsibleError, AnsibleOptionsError
+from ansible.errors import AnsibleError, AnsibleOptionsError, AnsibleParserError
 from ansible.module_utils._text import to_bytes, to_native
 from ansible.module_utils.parsing.convert_bool import boolean
 from ansible.module_utils.six import string_types
@@ -80,6 +81,9 @@ class BaseInventoryPlugin(object):
         pass
 
     def populate_host_vars(self, hosts, variables, group=None, port=None):
+        if not isinstance(variables, MutableMapping):
+            raise AnsibleParserError("Invalid data from file, expected dictionary and got:\n\n%s" % to_native(variables))
+
         for host in hosts:
             self.inventory.add_host(host, group=group, port=port)
             for k in variables: