Download the rpm and run it with the correct RAILS_ENV for your setup.
wget http://www.avalonmediasystem.org/downloads/avalon-sample-content-3.0-1.noarch.rpm RAILS_ENV="development" rpm -i --force avalon-sample-content-3.0-1.noarch.rpm
If running a manual installation, a hard link needs to be created so that the rpm can find avalon in the '/var/www/avalon/current' directory.
Example:
ln -s /var/www/avalon/ /var/www/avalon/current