/build contains a Phing buildfile that will install (or update) a working WordPress development install. You will need to install Phing:

$ pear install -f --alldeps phing/phing

To run:

cd /path/to/workingcopy
cd build
phing

Optionally, you can just grab /build/src/wp-config.php for your current dev environment. The wp-config.php file contains standardized settings for your WordPress development environment.