fixed missing default (#69972)

* fixed missing default

 also deprecated so new options wont have to go through this

changelogs/fragments/deprecate_default_call_fragmentless.yml

@@ -0,0 +1,4 @@
+deprecated_features:
+  - Using the DefaultCallback without the correspodning doc_fragment or copying the documentation.
+bugfixes:
+  - added new option for default callback to compat variable to avoid old 3rd party plugins from erroring out.

lib/ansible/plugins/callback/default.py

@@ -43,7 +43,6 @@ from ansible.playbook.task_include import TaskInclude
 from ansible.plugins.callback import CallbackBase
 from ansible.utils.color import colorize, hostcolor
 
-
 # These values use ansible.constants for historical reasons, mostly to allow
 # unmodified derivative plugins to work. However, newer options added to the
 # plugin are not also added to ansible.constants, so authors of derivative
@@ -57,7 +56,8 @@ COMPAT_OPTIONS = (('display_skipped_hosts', C.DISPLAY_SKIPPED_HOSTS),
                   ('display_ok_hosts', True),
                   ('show_custom_stats', C.SHOW_CUSTOM_STATS),
                   ('display_failed_stderr', False),
-                  ('check_mode_markers', False),)
+                  ('check_mode_markers', False),
+                  ('show_per_host_start', False))
 
 
 class CallbackModule(CallbackBase):
@@ -88,6 +88,8 @@ class CallbackModule(CallbackBase):
             try:
                 value = self.get_option(option)
             except (AttributeError, KeyError):
+                self._display.deprecated("'%s' is subclassing DefaultCallback without the corresponding doc_fragment." % self._load_name,
+                                   version='2.14')
                 value = constant
             setattr(self, option, value)