Dupliframes not rendered in Cycles? As became apparent after my attempt to  answer to a recent BSE Question..

It seems that Dupliframes are not rendered in Cycles Preview or Final? (They are rendered by Blender Internal) 

This is true of two recent builds of 2.79. Windows 10, Nvidia 840m

Is this just a missing setting, expected behaviour, or a bug?

If it is  a bug, is bug reporting still accepted for Blender 2.79, or has everything moved on to 2.8?
Ok, got the answer.. it was a setting. 

By accident, in two files from different users, Duplication was set to 'Frames' not only on the Dupli object, but also on its parent curve. I guess it must be an easy slip to make.

I would delete the question, but I've referred to it from elsewhere, so I'll leave it for a bit before deleting it, and the comments which reference it.