How to change conf. for your environment.
Arscons needs to know the directories where AVR binaries and Arduino libraries reside. There are several ways to point it at the right directories. The precedence is:
to find out default options, find "ARGUMENTS.get(..)"s in SConstruct.
On Windows, or if you installed Arduino somewhere other than the default location for your platform, you will likely need to set ARDUINO_HOME. It's probably easiest to set the environment variable, assuming you plan to have a bunch of Arduino sketches in different directories.
Give arbitrary board name to ARDUINO_BOARD.
$ scons ARDUINO_BOARD=help
arscons uses Arduino's board.txt to select proper MCU, F_CPU, UPLOAD_PROTOCOL and UPLOAD_SPEED.
For Arduino NG(atmega8), using external reset trigger(reset.py), add my_libs/ for arduino library directory.
$ scons upload ARDUINO_BOARD=atmega8 RST_TRIGGER=./reset.py EXTRA_LIB=./my_libs ARDUINO_VER=19