Log removal from pool due to prereq being removed at INFO level

cylc/flow/scheduler.py

@@ -1140,7 +1140,7 @@ def remove_tasks(
                 ):
                     continue
                 # No longer has reason to be in pool:
-                self.pool.remove(child_itask, 'prerequisite task(s) removed')
+                self.pool.remove(child_itask, self.pool.REMOVED_BY_PREREQ)
                 # Remove this downstream task from flows in DB tables to ensure
                 # it is not skipped if it respawns in future:
                 self.workflow_db_mgr.remove_task_from_flows(

cylc/flow/task_pool.py

@@ -121,6 +121,7 @@ class TaskPool:
     ERR_TMPL_NO_TASKID_MATCH = "No matching tasks found: {0}"
     ERR_PREFIX_TASK_NOT_ON_SEQUENCE = "Invalid cycle point for task: {0}, {1}"
     SUICIDE_MSG = "suicide trigger"
+    REMOVED_BY_PREREQ = "prerequisite task(s) removed"
 
     def __init__(
         self,
@@ -875,6 +876,8 @@ def remove(self, itask: 'TaskProxy', reason: Optional[str] = None) -> None:
             ):
                 level = logging.WARNING
                 msg += " - active job orphaned"
+            elif reason == self.REMOVED_BY_PREREQ:
+                level = logging.INFO
 
             LOG.log(level, f"[{itask}] {msg}")
 

tests/integration/test_remove.py

@@ -362,6 +362,10 @@ async def test_prereqs(
         # Should cause 1/x to be removed from the pool as it no longer has
         # any satisfied prerequisite tasks:
         assert not schd.pool._get_task_by_id('1/x')
+        assert log_filter(
+            logging.INFO,
+            regex=r"1/x.* removed .* prerequisite task\(s\) removed",
+        )
 
 
 async def test_downstream_preparing(flow, scheduler, start):