Cask AdoptOpenJDK8 existe en múltiples grifos:
rm /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask-versions/Casks/adoptopenjdk8.rb
Defiant Dragonfly
rm /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask-versions/Casks/adoptopenjdk8.rb