backuppc_config.rb:
  The following ruby modules are required:
    - fileutils
    - optparse
    - ostruct
    - pp

  $ sudo gem install fileutils optparse ostruct pp

net.sourceforge.backuppc.plist:
  This is a launchdaemon script which starts backuppc at boot and keeps it
  running if the process dies for whatever reason.

  $ sudo cp net.sourceforge.backuppc.plist /Library/LaunchDaemons/