I want to install screen, but what should I do next?
$ brew search screen
imgur-screenshot screen screenfetch screenresolution
caskroom/drivers/casio-screen-receiver caskroom/cask/screen-blacker caskroom/cask/show-my-screen caskroom/cask/syphon-virtual-screen
If you meant "screen" specifically:
It was migrated from homebrew/dupes to homebrew/core.
homebrew/dupe is now deprecated all its formula have been migrated to the main repository (homebrew/core). As screen is now in homebrew/core, you just have to do:
brew install screen
but if you want you can install other third-party repositories (e.g. homebrew/science), called taps in the homebrew terminology, with:
brew tap homebrew/science
You can then directly installed all formulas in this tap. You can also install a formula from an uninstalled tap with:
brew install homebrew/science/<formula>
To list all your installed taps:
brew tap
To remove a tap:
brew untap homebrew/science
来源：https://stackoverflow.com/questions/45124717/whats-the-migration-from-homebrew-dupes-to-homebrew-core