This is a versioned cask repo of the anka-virtualization packages, so you can use specific versions.
Originally part of https://github.com/bitrise-io/homebrew-cask
brew install bitrise-io/anka-cask/<formula>
Or brew tap bitrise-io/anka-cask and then brew install <formula>.
brew help, man brew or check Homebrew's documentation.