Many thanks for the very prompt reply and help! The dummy stub should/would indeed fix it.
Meanwhile, through a process of removing/returning source-lines, removing line 32 viz. fadeENB[led] = random() & 1; removed the error.
Changing this line...
Could someone please advise/help with the following build problem...
The code below (.ino file, to randomly fade a small bunch of LEDs on an old Teensy LC) gives the following error when compiling or linking...