brew/docs/brew-tap.md

Taps (third-party repositories)

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)

• 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. Full is the default for Homebrew developers.

• 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 homebrew/core, that's fine, but it means that you must install it explicitly by default.

If you would like to prioritize a tap over homebrew/core, you can use brew tap-pin username/repo to pin the tap, and use brew tap-unpin username/repo to revert the pin.

Whenever a brew install foo command is issued, brew will find which formula to use by searching in the following order:

• Pinned taps
• Core formulae
• Other taps

If you need a formula to be installed from a particular tap, you can use fully qualified names to refer to them.

For example, you can create a tap for an alternative vim formula. Without pinning it, the behavior will be

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

However if you pin the tap with brew tap-pin username/repo, you will need to use homebrew/core to refer to the core formula.

brew install vim                     # installs from your custom repo
brew install homebrew/core/vim       # installs from homebrew/core

Do note that pinned taps are prioritized only when the formula name is directly given by you. i.e., it will not influence formulae automatically installed as dependencies.