re-enable workflow mode = skip doing something useufl

cylc/flow/cfgspec/workflow.py

@@ -1339,7 +1339,6 @@ def get_script_common_text(this: str, example: Optional[str] = None):
             Conf(
                 'run mode', VDR.V_STRING,
                 options=list(RunMode.OVERRIDING_MODES.value),
-                default=RunMode.LIVE.value,
                 desc=f'''
                     For a workflow run in live mode run this task in skip
                     mode.

cylc/flow/task_job_mgr.py

@@ -1009,14 +1009,21 @@ def _nonlive_submit_task_jobs(
         workflow: str,
         workflow_run_mode: str,
     ) -> 'Tuple[List[TaskProxy], List[TaskProxy]]':
-        """Simulation mode task jobs submission.
+        """Identify task mode and carry out alternative submission
+        paths if required:
+
+        * Simulation: Job submission.
+        * Skip: Entire job lifecycle happens here!
+        * Dummy: Pre-submission preparation (removing task scripts content)
+          before returning to live pathway.
+        * Live: return to main submission pathway without doing anything.
 
         Returns:
             lively_tasks:
                 A list of tasks which require subsequent
                 processing **as if** they were live mode tasks.
                 (This includes live and dummy mode tasks)
-            ghostly_tasks:
+            nonlive_tasks:
                 A list of tasks which require no further processing
                 because their apparent execution is done entirely inside
                 the scheduler. (This includes skip and simulation mode tasks).
@@ -1027,33 +1034,38 @@ def _nonlive_submit_task_jobs(
         now = (now, get_time_string_from_unix_time(now))
 
         for itask in itasks:
-            # Handle broadcasts:
+            # Get task config with broadcasts applied:
             rtconfig = self.task_events_mgr.broadcast_mgr.get_updated_rtconfig(
                 itask)
+
             # Apply task run mode
             if workflow_run_mode in RunMode.NON_OVERRIDABLE_MODES.value:
                 # Task run mode cannot override workflow run-mode sim or dummy:
                 run_mode = workflow_run_mode
             else:
-                # TODO - check whether this ever falls back on workflow run mode
-                run_mode = rtconfig['run mode'] or workflow_run_mode
+                # If workflow mode is skip or live and task mode is set,
+                # override workflow mode, else use workflow mode.
+                run_mode = rtconfig.get('run mode', None) or workflow_run_mode
+            # Store the run mode of the this submission:
             itask.run_mode = run_mode
-            # Submit nonlive tasks, or add live-like tasks to list
-            # of tasks to put through live submission pipeline -
-            # We decide based on the output of the submit method:
-            is_done = False
+
+            # Submit nonlive tasks, or add live-like (live or dummy)
+            # tasks to list of tasks to put through live
+            # submission pipeline - We decide based on the output
+            # of the submit method:
+            is_nonlive = False
             if run_mode == RunMode.DUMMY.value:
-                is_done = dummy_submit_task_job(
+                is_nonlive = dummy_submit_task_job(
                     self, itask, rtconfig, workflow, now)
             elif run_mode == RunMode.SIMULATION.value:
-                is_done = simulation_submit_task_job(
+                is_nonlive = simulation_submit_task_job(
                     self, itask, rtconfig, workflow, now)
             elif run_mode == RunMode.SKIP.value:
-                is_done = skip_submit_task_job(
+                is_nonlive = skip_submit_task_job(
                     self, itask, rtconfig, now)
 
             # Assign task to list:
-            if is_done:
+            if is_nonlive:
                 nonlive_tasks.append(itask)
             else:
                 lively_tasks.append(itask)

tests/integration/run_modes/test_mode_overrides.py

@@ -51,8 +51,16 @@ async def test_run_mode_override_from_config(
 
         # Live task has been really submitted:
         assert log_filter(log, contains=expect_template.format('live'))
-        # Default is the same as live:
-        assert log_filter(log, contains=expect_template.format('default'))
+
+        # Default is the same as workflow:
+        if workflow_run_mode == 'live':
+            assert log_filter(log, contains=expect_template.format('default'))
+        else:
+            assert log_filter(
+                log, contains='[1000/default_/01:running] => succeeded')
+            assert not log_filter(
+                log, contains=expect_template.format('default'))
+
         # Skip task has run, but not actually been submitted:
         assert log_filter(log, contains='[1000/skip_/01:running] => succeeded')
         assert not log_filter(log, contains=expect_template.format('skip'))