Tips N' Tricks

Package versions

show and switch

brew versions python3
3.2.3    git checkout 83b3771 /usr/local/Library/Formula/python3.rb
3.2.2    git checkout f3408c9 /usr/local/Library/Formula/python3.rb
3.2.1    git checkout 949d521 /usr/local/Library/Formula/python3.rb
3.2      git checkout 83ed494 /usr/local/Library/Formula/python3.rb
...
brew switch python3 3.2.2

Installing directly from pull-requests

You can browse pull requests https://github.com/mxcl/homebrew/pulls and install through the direct link. For example Python 3.3.0 pull request https://github.com/mxcl/homebrew/pull/15199

brew install https://raw.github.com/dsr/homebrew/9b22d42f50fcbc5e52c764448b3ac002bc153bd7/Library/Formula/python3.rb

Quickly remove something from /usr/local

brew unlink foo

This can be useful if a package can't build against the version of something you have linked into /usr/local.

And of course, you can simply brew link foo again afterwards!

Install into Homebrew without formulas

./configure --prefix=/usr/local/Cellar/foo/1.2 && make && make install && brew link foo

Command tab-completion

Bash

Add to your ~/.bashrc or ~/.bash_profile (whichever you have configured to run on shell startup):

source `brew --prefix`/Library/Contributions/brew_bash_completion.sh

ZSH

Run in terminal:

mkdir -p ~/.zsh/func
ln -s "$(brew --prefix)/Library/Contributions/brew_zsh_completion.zsh" ~/.zsh/func/_brew

Add to your ~/.zshrc:

fpath=($HOME/.zsh/func $fpath)
typeset -U fpath

Pre-downloading a file for a formula

Sometimes it's faster to download a file via means other than those strategies that are available as part of Homebrew. For example, Erlang provides a Torrent that'll let you download at 4–5× the normal HTTP method. Download the file and drop it in ~/Library/Caches/Homebrew, but watch the file name. Homebrew downloads files as {{ formula name }}-{{ version }}. In the case of Erlang, this requires renaming the file from otp_src_R13B03 to erlang-R13B03.

New:

mv the_tarball `brew --cache formula-name`

You can also pre-cache the download by using the command brew fetch formula which also displays the MD5. This can be useful for updating formulae to new versions.

Using Homebrew behind a proxy

Behind the scenes, Homebrew uses several commands for downloading files (e.g. curl, git, svn). Many of these tools can download via a proxy. It's a common (though not universal) convention for these command-line tools to observe getting the proxy parameters from environment variables (e.g. http_proxy). Unfortunately, most tools are inconsistent in their use of these environment parameters (e.g. curl supports http_proxy, HTTPS_PROXY, FTP_PROXY, GOPHER_PROXY, ALL_PROXY, NO_PROXY).

Luckily, for the majority of cases setting http_proxy is enough. You can set this environment variable in several ways (search on the internet for details), but the way I prefer is:

$ http_proxy=http://<proxyhost>:<proxyport>  brew install foo

Proxy Authentication

$ http_proxy=http://<user>:<password>@<proxyhost>:<proxyport>  brew install foo

NB: this technique will also work if you prefer to use sudo with Homebrew. But as sudo clears the environment before executing Homebrew, your proxy settings may get lost.

Workaround:

$ http_proxy=http://<proxyhost>:<proxyport>  sudo -E brew install foo

Installing stuff without the Xcode-CLT

$ brew sh          # or: eval $(brew --env)
$ gem install ronn # or c-programs

This imports the brew environment into your existing shell, gem will pick up the environment variables and be able to build. As a bonus brew's automatically determined optimization flags are set.

Install a formula's dependencies without installing the formula itself

brew install `brew deps foo`

brew irb

$ brew irb
1.8.7 :001 > Formula.factory("ace").methods - Object.methods
 => [:install, :path, :homepage, :downloader, :stable, :bottle, :devel, :head, :active_spec, :buildpath, :ensure_specs_set, :url, :version, :specs, :mirrors, :installed?, :explicitly_requested?, :linked_keg, :installed_prefix, :prefix, :rack, :bin, :doc, :include, :info, :lib, :libexec, :man, :man1, :man2, :man3, :man4, :man5, :man6, :man7, :man8, :sbin, :share, :etc, :var, :plist_name, :plist_path, :download_strategy, :cached_download, :caveats, :options, :patches, :keg_only?, :fails_with?, :skip_clean?, :brew, :std_cmake_args, :deps, :external_deps, :recursive_deps, :system, :fetch, :verify_download_integrity, :fails_with_llvm, :fails_with_llvm?, :std_cmake_parameters, :mkdir, :mktemp] 
1.8.7 :002 >

Hiding the beer can emoji when finishing a build

export HOMEBREW_NO_EMOJI=1

This sets the HOMEBREW_NO_EMOJI environment variable, causing homebrew to hide all emoji.