These scripts can be used to bundle a .dmg installer of StepMania. It assumes you have already built a StepMania.app using Xcode and that your stepmania directory structure is intact as you cloned it.
To bundle a release version of StepMania open a terminal and cd to your stepmania directory, then run the following commands:
cd Xcode/scripts
ruby mkrelease.rb
This will create a disk image like StepMania-v5.0-beta-4-mac.dmg in the root of your stepmania directory.
To bundle an intermediate or "nightly" .dmg installer, cd to your stepmania directory, and run the following commands:
cd Xcode/scripts
ruby mkrelease.rb nightly
This will create a disk image like StepMania-v5.0-31-8-2014-mac.dmg in the root of your stepmania directory.