maniacbug:
Interesting, I see it's not working out of the box with maniacbug-mighty-1284p__vector_20 is USART0_RX_vect. The 1284P defines the USART0 vectors, HardwareSerial picks them up. Shouldn't this also have the same problem on a Mega?
Looks like this library is demanding access to the USART0_RX_vect?
Oh? I was able to build a few of the examples that came with this library using your cores. I had suspected it was a core issue, but after I was able to build the examples I assumed it must be my code.
If I remove the HardwareSerial.cpp file, then the compilation fails. Its getting dragged in somewhere.