#if ARDUINO_VERSION < 12#error "Whoops!"#endif
In my experience, there are a number of users -- GekoCH here for example -- that like to stick with earlier versions of Arduino. There are a number of "stale" libraries that no longer work on the newer Arduino versions. That's frequently the motivation for staying with one version. Is that the case here, GekoCH?
/* asm volatile("sbiw %0, 0x01 \n\t" "ldi %1, 0xFF \n\t" "cpi %A0, 0xFF \n\t" "cpc %B0, %1 \n\t" "brne .-10 \n\t" : "+r" (delay), "+a" (tmp) : "0" (delay) );*/
/tmp/ccdD9LWq.s: Assembler messages:/tmp/ccdD9LWq.s:855: Error: register r24, r26, r28 or r30 required/tmp/ccdD9LWq.s:912: Error: register r24, r26, r28 or r30 required/tmp/ccdD9LWq.s:957: Error: register r24, r26, r28 or r30 requiredo: In function `main':undefined reference to `NewSoftSerial::NewSoftSerial(unsigned char, unsigned char)'