brew/share/doc/homebrew/brew-tap.md

brew tap

tl;dr brew tap adds more repos to the list of formulae that brew tracks, updates, and installs from. By default, tap assumes that the repos come from GitHub, but the command isn't limited to any one location.

The command

• brew tap without arguments lists the currently tapped repositories. For example:

$ brew tap
homebrew/dupes
mistydemeo/tigerbrew
edavis/emacs

• brew tap <user/repo> makes a shallow clone of the repository at https://github.com/user/repo. After that, brew will be able to work on those formulae as if there were in Homebrew's canonical repository. You can install and uninstall them with brew [un]install, and the formulae are automatically updated when you run brew update. (See below for details about how brew tap handles the names of repositories.)

• brew tap <user/repo> <URL> makes a shallow clone of the repository at URL. Unlike the one-argument version, URL is not assumed to be GitHub, and it doesn't have to be HTTP. Any location and any protocol that git can handle is fine.

• Add --full to either the one- or two-argument invocations above, and git will make a complete clone rather than a shallow one.

• brew tap --repair migrates tapped formulae from symlink-based to directory-based structure. (This should only need to be run once.)

• brew untap user/repo [user/repo user/repo ...] removes the given taps. The repos are deleted and brew will no longer be aware of its formulae. brew untap can handle multiple removals at once.

Repository naming conventions and assumptions

• On GitHub, your repository must be named homebrew-something in order to use the one-argument form of brew tap. The prefix 'homebrew-' is not optional. (The two-argument form doesn't have this limitation, but it forces you to give the full URL explicitly.)

• When you use brew tap on the command line, however, you can leave out the 'homebrew-' prefix in commands.

  That is, brew tap username/foobar can be used as a shortcut for the long version: brew tap username/homebrew-foobar. brew will automatically add back the 'homebrew-' prefix whenever it's necessary.

Formula duplicate names

If your tap contains a formula that is also present in master, that's fine, but it means that you must install it explicitly.

For example, you can create a tap for an alternative vim formula, but in that case when you install from there you must run the command with a more explicit installation target:

brew install vim                 # installs from Homebrew/homebrew
brew install username/repo/vim   # installs from your custom repo