Indeed, it appears to work.
Now the Arduino IDE says it's using /dev/ttyACM0 which does NOT appear to exist. Exactly how's this working?
BTW, do I need an OTG cable? Currently, it's the only mini-USB cable I have.
You might try doing "dmesg | tail" from a terminal window. This dumps the end of the Linux kernel message buffer. Do this without the ISP connected and again after it has been connected. It should either show a few lines on how the device connected or some indication as to why it did not connect.
If the ISP is connecting successfully as /dev/ttyACM0, this means the kernel is recognizing it as a modem device. This may be "working as designed" for the ISP, but it's possible your Linux installation is configured to fire up some modem service conflicting with avrdude. If so that service would need to be disabled. I've seen this sort of thing on Ubuntu systems on devices that register as ACM types. One would, however, expect some obvious failure message from avrdude in this instance.