As I’ve started exploring some of the more exotic members of the ATtiny family, I have increasingly been clashing with the fairly old AVR toolchain included in the Arduino IDE. I understand that there is little upside for the Arduino project in upgrading their tools: The current versions support the ATmegas on which official Arduinos are based just fine.
There are, of course, a lot of people simply using avr-gcc and avrdude with makefiles and generic text editors, but personally, the Arduino IDE suits me just fine for most of my projects.
After a few months of replacing bits and pieces of the toolchain, I’ve arrived at a more principled approach, based on CrossPack, a well maintained distribution of up to date versions of the AVR tools for OS X, including patches for the latest processors. After installing CrossPack from the web site, the following script will replace the toolchain in the Arduino IDE with a link to the CrossPack toolchain: