Hmmph. My Mac doesn't seem to like driving FTDI chips at 1Mbps...
Overriding Baud Rate : 1000000
avrdude: serial_baud_lookup(): Using non-standard baud rate: 1000000avrdude: ser_setspeed(): tcsetattr() failed
avrdude: ser_open(): can't set attributes for device "/dev/tty.usbserial-AM01QQUY": Invalid argument