Sharing a tip.
Using the Arduino ISP programmer I got the annoying messages from avrdude asking to define PAGEL and BS2. Since the ATtinyX5 family doesn't have these pins, and I guess we don't actually need them, I defined them in AVRDUDE.CONF to be pins/ports that don't exist - no more error messages.
# PAGEL and BS2 defined by --RL so we don't get a warning error from avrdude n/a on attiny85
pagel = 0xD0; # these don't exist on the ATtinyX5 series
bs2 = 0xD1; # these don't exist on the ATtinyX5 series
You can find AVRDUDE.CONF in
arduino-0022\hardware\tools\avr\etc