No :-( - It does not throw an error but 0 rows are affected.
Actually I tried smart_merge as well.
merge delta of _sys_repo.active_object WITH PARAMETERS ('FORCED_MERGE' = 'ON')
MERGE DELTA OF _sys_repo.active_object WITH PARAMETERS('SMART_MERGE' = 'ON');
Statement 'merge delta of _sys_repo.active_object WITH PARAMETERS ('FORCED_MERGE' = 'ON')'
successfully executed in 3.818 seconds (server processing time: 2.811 seconds) - Rows Affected: 0