A public Homebrew tap containing alternate versions of casks.
Casks cannot be versioned. Running brew cask install my_app will install whichever version of my_app the cask is designed to install. You get what you get, which is often the latest available version of an application.
What happens if you need an older version of something? Or you need a to use a different supported version of something? Specifying an arbitrary version of an application is not possible.
However, you can create your own repo (which must be named homebrew-*) to contain your own set of customized casks, which will install your required versions of things. Then you can connect to that repo with the brew tap command. That way, when brew looks for a cask named my_app, it will use the one from your repo. Version control achieved!
Note: Private taps can be prioritized over public taps by using the brew tap-pin command. However, this only works with formulas, not casks.
Add a cask to /Casks which will install my_app.
Tap the repo:
brew tap daptiv/homebrew-tapThen install the cask just like normal:
brew cask install daptiv/homebrew-tap/my_app