Integrity is your friendly automated Continuous Integration server.
There has been various issues of regarding thin, sinatra, rack version dependancy which makes integrity setup painful, Wholly Team has tried to simplify the process
$ git clone git://github.com/wholly/integrity.git
$ gem install sinatra-sinatra -s http://gems.github.com
$ gem install thin do_sqlite3
$ gem install oauth
$ gem install -s http://gems.github.com jstewart-yammer4r
$ cp config/config.sample.ru config/config.ru
$ cp config/config.sample.yml config/config.yml (Change contents to suite your needs)
$ thin -C config/config.yml -R config/config.ru start
$ bin/integrity migrate_db
$ mkdir /tmp/integrity-exports/cache
$ mkdir the builds directory which you mentioned in the config.yml
$ open http://0.0.0.0:3000/