Where are my node log files?

edit

We have a system with a few dozen nodes, started from a top-level launch file consisting mostly of <include> tags. Most of them are rospy nodes, but some are roscpp. Looking in ~/.ros/log I see that node log files exist for <10 nodes. I can't see any pattern as to why a few nodes would make log files, but not others. There are no logs in the $ROS_ROOT tree. None of our launch files specify the output attribute in the <node> tag, so I would expect there to be a log file for every node, since the default is log. We're running Indigo on Ubuntu 14.

I feel like I'm missing something really obvious. Any advice is greatly appreciated.