WARNING -- Companion9x currently installs a broken avrdude, here's how to fix it!!!
This makes it look like your 9x or 9xr is broken, but it's actually avrdude that's broken.
You can use HomeBrew to install a working avrdude. Follow the brew install instructions, and then type
brew install avrdude
Note that to get HomeBrew working, you need to
- install or update Xccode to the latest version
- install Command Line Tools from Xcode / Preferences / Downloads / Components
Hopefully the Companion9x people will remedy the situation. I'll report it to them.
MANY THANKS to 4x4rc on rcgroups for alerting me to this before I shipped my 9xr back to HK!!