I was having some trouble getting avr-gcc to compile arduino sketches on Arch Linux using the Makefile from ardunio.cc. This is my modified Makefile, that now works OK. I'm using the Arduino AUR package.
The first time you use this Makefile you'll need to run a sudo make - or su equivalent - the permissions on the AUR package directory (rightly) do not permit user writes, and the Makefile needs to create the initial versions of some libraries.
I also found it necessary to apply the diff from comment 3 of this thread against Print.cpp and Print.h in the arduino core directory installed by the AUR package (changes the diff makes to files other than these two can be ignored). Otherwise there will be warnings about the Print.o library.
Now make and make upload should work properly!
You will have to change the MCU=atmega328p line if you're not on a Duemilanove like me.