How to enable writing to coreduetd.log In Yosemite, there is a log file here:

/private/var/log/coreduetd.log


...but it's always empty.
How do I make the system write events to it, assuming there are any?
Unless you know that you've tinkered with the permissions on the file, it should be:


  -rw-r--r--  1 root  wheel  0 Oct 18 11:02 /private/var/log/coreduetd.log


This logfile is empty on the 5 Yosemite Macs I have access to.