[avr-chat] avrdude ignores defaults?

[Rick Mann]

Hi. I'm using avrdude 5.11.1 on OS X 10.8.3. I've got the following in 
~/.avrduderc:

> default_programmer = "avrisp2";
> default_serial = "usb";
> 
I'm invoking it like this:

> $ avrdude -c dragon_jtag -p x256a3b 
> avrdude: ser_open(): can't open device "unknown": No such file or directory
> ?

But if I invoke it with an explicit port, it works:

> $ avrdude -c dragon_jtag -p x256a3b -P usb
> 
> avrdude: AVR device initialized and ready to accept instructions
> 
> Reading | ################################################## | 100% 0.02s
> 
> avrdude: Device signature = 0x1e9843
> 
> avrdude done.  Thank you.

(Although it seems to cause the AVR Dragon to disconnect from and reconnect to 
the USB.)

Why doesn't it automatically find it on USB?

Thanks,

-- 
Rick