The Shaka Lab project is all the software needed to replicate the private lab environment used to build and test Shaka Player, Shaka Packager, and others.
Homebrew taps (which host macOS package formulae) require a specific GitHub naming convention and repository layout, which this repository satisfies. It is built and deployed automatically from shaka-project/shaka-lab.
For more information, original sources, or to file issues, please see shaka-project/shaka-lab.