Latest version of cgminer works fine with RPi and erupters without using ancient tty port settings. It should just autodetect them. Note that RPis can't drive USB3 hubs since they have no usb3 drivers so if yours is USB3, you're out of luck unless you put yet another usb2 hub between that hub and the Pi.
I just downloaded 3.8.1 from your github. I'm going to attempt it with that. I believe the USB hub is 2.0 as well.