What really happened to the U.S. train-and-equip program in Syria?

What really happened to the U.S. train-and-equip program in Syria? | McClatchy DC: 

On July 31, Nusra attacked the headquarters of the division in a battle that ended with U.S. airstrikes and ground intervention by Kurdish militias. As many as 50 Nusra members died in the fighting, according to some reports, but Nusra managed to seize 10 graduates of the so-called train-and-equip program.
Ten weeks later, the Pentagon announced that it had halted the program, which until that moment had been the keystone of the Obama administration’s policy to combat the Islamic State, also known as ISIS and ISIL, in Syria.
The program’s demise has been ascribed to a number of factors, including the participants, the Turkish intelligence agency MIT and a Syrian militia, the Kurdish People’s Protection Units, better known as the YPG.