Gaster built for Windows using libUsbK driver tries to patch an 8950 device (in my case, iPhone 5) and after that device reboots.
Under Linux (Ubuntu) patching can stop at some step and Gaster stops responding. If patching succeeds, the descriptor becomes unrecognizable and applying the patch becomes impossible until the next reboot to DFU. Gaster tries to patch all over again.
So, it seems pwning A6 devices is impossible atm.

