emulator -avd Nexus_5X_API_19 -qemu -serial /dev/tty.usbserial-FTFV0GEN

emulator: WARNING: encryption is off
Hax is enabled
Hax ram_size 0x60000000
HAX is working and emulator runs in fast virt mode.
qemu-system-i386: -serial /dev/tty.usbserial-FTFV0GEN: chardev: backend "tty" not found
qemu-system-i386: -serial /dev/tty.usbserial-FTFV0GEN: could not connect serial device to character backend '/dev/tty.usbserial-FTFV0GEN'

Result Code:
NS_ERROR_FAILURE (0x80004005)
Component:
SessionMachine
Interface:
ISession {7844aa05-b02e-4cdd-a04f-ade4a762e6b7}