fatal error: avr/io.h: No such file or directory

Question

I'm compiling a project on Due that was working correclty using UNO. I get this error : 'avr/io.h: No such file or directory'. Searching across the web, it seams I'm not the only one to get that error when using Arduino Due but didn't clearly figured out why it appears.

Of course, the file is present where it should be, I verified ..\Arduino\hardware\tools\avr\avr\include\avr\io.h

I opened it and see something like that :

...
#if defined (__AVR_AT94K__)
# include <avr/ioat94k.h>
#elif defined (__AVR_AT43USB320__)
# include <avr/io43u32x.h>
#elif defined (__AVR_AT43USB355__)
# include <avr/io43u35x.h>
#elif defined (__AVR_AT76C711__)
# include <avr/io76c711.h>
#elif defined (__AVR_AT86RF401__)
# include <avr/io86r401.h>
#elif defined (__AVR_AT90PWM1__)
# include <avr/io90pwm1.h>
#elif defined (__AVR_AT90PWM2__)
# include <avr/io90pwmx.h>
#elif defined (__AVR_AT90PWM2B__)
# include <avr/io90pwm2b.h>
#elif defined (__AVR_AT90PWM3__)
# include <avr/io90pwmx.h>
#elif defined (__AVR_AT90PWM3B__)
# include <avr/io90pwm3b.h>
#elif defined (__AVR_AT90PWM216__)
# include <avr/io90pwm216.h>
#elif defined (__AVR_AT90PWM316__)
# include <avr/io90pwm316.h>
#elif defined (__AVR_AT90PWM161__)
# include <avr/io90pwm161.h>
#elif defined (__AVR_AT90PWM81__)
# include <avr/io90pwm81.h>
...

so I suppose that a line referring to my card is missing or something like that ?

I'm using Arduino 1.6.12

Answer 1

The Due is SAM architecture. avr/io.h is specific to the AVR architecture of the Uno's microcontroller. The compiler will not look in the avr tools folder for that file and even if it did it wouldn't help because that file is not compatible with the SAM architecture.

This error indicates that part of the code you're attempting to compile (probably a library) is AVR specific. You will need to either port that code to the SAM architecture or find an alternative that is already compatible with Due.