spotify/luigi — pull request #316 by freider (2014-04-23 15:38:57+00:00)
Title: Use process locking by default when running on command line

The --lock options has the advantage that a luigi line in cron or on the command line will never spawn a new luigi worker while the same trigger line (typically from the last hour) is still running.
It's desirable to have this functionality be the default since workers could otherwise be arbitrarily spawned and not limited by the --workers flag on the line in question.