The User Guide instructions tell us
apio drivers --serial-enable, which requires homebrew.
I installed homebrew, reluctantly since (a) I already have macports and (b) I don’t like the way homebrew tramples over
/usr/local, but then I noticed that
tinyprog uses USB anyway! so I uninstalled homebrew (delete
/usr/local/*, restore from backup) and reinstalled the tools without any
apio drivers, and am progressing happily.
Aside, that is, from the way that
tinyprog takes 5-10 seconds before doing anything, every time.
I tried the
LIBUSB_DEBUG=4 suggested earlier, and found that the delay happens at the
[ 0.038955]  libusb: debug [libusb_get_device_list] [ 5.040500]  libusb: debug [libusb_get_device_descriptor]
Running with Mojave 10.14.1, libusb v188.8.131.5212, apio 0.4.0, latest tinyprog.