@robert-chiniquy It seems that, before those two commits, if user does not specify a PID file path, it will results in not writing a PID file.

Check out this: https://github.com/racker/virgo/blob/master/util/misc.lua#L57 , in which if pidfile is null, nothing gets done; and the function is called here: https://github.com/racker/virgo/commit/6c5e36761f29b1f717ab7f24fbab4e6a646b3119#L0L75 , where before the above commit, no default value overwriting null values.