MrsDos:
Hi, shmusher,Had the same error with naked-functions. Try making the variable sreg global (comment/delete all definitions "unsigned char sreg;" inside all the functions in kernel.cpp file and make one at the very beginning). That works for me (Ubuntu 14.04 & Arduino 1:1.0.5+dfsg2-2).
thank you soooo much.................. 
it worked for me too. you made my day.