handle refusal with an exception

koji/daemon.py

@@ -1504,6 +1504,9 @@ class TaskManager(object):
         except (SystemExit, koji.tasks.ServerExit, KeyboardInterrupt):
             # we do not trap these
             raise
+        except koji.tasks.RefuseTask as refuse:
+            self.session.host.refuseTask(handler.id, msg=str(refuse))
+            return
         except koji.tasks.ServerRestart:
             # freeing this task will allow the pending restart to take effect
             self.session.host.freeTasks([handler.id])

koji/tasks.py

@@ -110,6 +110,11 @@ class ServerRestart(Exception):
     pass
 
 
+class RefuseTask(Exception):
+    """Raise to task handler to refuse a task"""
+    pass
+
+
 def parse_task_params(method, params):
     """Parse task params into a dictionary