When trying to flash my sketch, I see many errors such as:
***failed;
***failed;
***failed;
avrdude: Error: butterfly programmer uses avr_write_page() but does not
provide a cmd() method.
*** page 127 (addresses 0x7400 - 0x747f) failed to write
And also:
avrdude: error: programmer did not respond to command: set addr
How can I successfully flash my sketch?