So I'm building local with the current develop branch on OS X with the instructions from the build docs.
When I add program-dfu to my command line it fails. I'm compiling from the top level firmware directory
Photon
make PLATFORM=photon APP=MPU6050_Test program-dfu
Building firmware for Production Photon, platform ID: 6, product ID: 6
make: *** No rule to make target `program-dfu'. Stop.
Core
make PLATFORM=core APP=MPU6050_Test program-dfu
Building firmware for Spark core, platform ID: 0, product ID: 0
make: *** No rule to make target `program-dfu'. Stop.
I have dfu-util 0.8 installed and can manually upload code to a core the old way.
dfu-util -d 1d50:607f -a 0 -s 0x08005000:leave -D Filename.bin
EDIT: clarified some extra details.