Due error, error: cannot declare variable 'Wire' to be of abstract type 'TwoWire' extern TwoWire Wire;

Official Hardware Mega Due
3 
...\sam\1.6.12\cores\arduino/Print.h:50:17: note: 	virtual int Print::availableForWrite()

     virtual int availableForWrite(void) = 0;

Where did this come from? There is no Print::availableForWrite() in SAM core, only serial classes (U(S)ART and CDC) have it.

This is how it is defined in ArduinoCore-API, won't cripple working code:

    // default to zero, meaning "a single write may block"
    // should be overridden by subclasses with buffering
    virtual int availableForWrite() { return 0; }