brew/share/doc/homebrew/FAQ.md

FAQ

How do I update my local packages?

First update the formulae and Homebrew itself:

brew update

You can now find out what is outdated with:

brew outdated

Upgrade everything with:

brew upgrade

Or upgrade a specific formula with:

brew upgrade $FORMULA

How do I stop certain formulae from being updated?

To stop something from being updated/upgraded:

brew pin $FORMULA

To allow that formulae to update again:

brew unpin $FORMULA

How do I uninstall old versions of a formula?

By default, Homebrew does not uninstall old versions of a formula, so over time you will accumulate old versions. To remove them, simply use:

brew cleanup $FORMULA

or clean up everything at once:

brew cleanup

to see what would be cleaned up:

brew cleanup -n

How do I uninstall Homebrew?

To uninstall Homebrew, paste the command below in a terminal prompt.

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"

Download the uninstall script and run ./uninstall --help to view more uninstall options.

How do I uninstall a formula?

If you do not uninstall all of the versions that Homebrew has installed, Homebrew will continue to attempt to install the newest version it knows about when you do (brew upgrade --all). This can be surprising.

To remove a formula entirely, you may do (brew uninstall formula_name --force).

Be careful as this is a destructive operation.

Where does stuff get downloaded?

brew --cache

Which is usually: /Library/Caches/Homebrew

My Mac .apps don’t find /usr/local/bin utilities!

GUI apps on OS X don’t have /usr/local/bin in their PATH by default. If you’re on Mountain Lion, you can fix this by running launchctl setenv PATH "/usr/local/bin:$PATH". More details here, including how to set this across reboots. If you’re pre-Mountain Lion, here’s an official alternative.

How do I contribute to Homebrew?

Read CONTRIBUTING.md.

Why do you compile everything?

Homebrew provides pre-compiled versions for some formulae. These pre-compiled versions are referred to as bottles and are available at: https://bintray.com/homebrew/bottles.

If available, bottled binaries will be used by default except under the following conditions:

• Options were passed to the install command i.e. brew install $FORMULA will use a bottled version of $FORMULA, but brew install $FORMULA —enable-bar will trigger a source build.
• The --build-from-source option is invoked.
• The environment variable HOMEBREW_BUILD_FROM_SOURCE is set.
• The machine is not running OS X 10.8+ as all bottled builds are generated on Mountain Lion or later.
• Homebrew is installed to a prefix other than the standard /usr/local (although some bottles support this)

In order to completely disable bottled builds, simply add a value for the environment variable HOMEBREW_BUILD_FROM_SOURCE to your profile.

We aim to bottle everything.

How do I get a formula from someone else’s branch?

brew install hub
brew update
cd $(brew --repository)
hub pull someone_else

Or:

brew install https://raw.github.com/user/repo/branch/formula.rb

Or:

brew pull https://github.com/Homebrew/homebrew/pulls/1234

Why does Homebrew insist I install to /usr/local?

1. It’s easier
   /usr/local/bin is already in your PATH.
2. It’s easier
   Tons of build scripts break if their dependencies aren’t in either /usr or /usr/local. We fix this for Homebrew formulae (although we don’t always test for it), but you’ll find that many RubyGems and Python setup scripts break which is something outside our control.
3. It’s safe
   Apple has left this directory for us. Which means there is no /usr/local directory by default, so there is no need to worry about messing up existing tools.

If you plan to install gems that depend on brews then save yourself a bunch of hassle and install to /usr/local!

It is not always straightforward to tell gem to look in non-standard directories for headers and libraries. If you choose /usr/local, many things will "just work".

Why does Homebrew say sudo is bad?

tl;dr Sudo is dangerous, and you installed TextMate.app without sudo anyway.

Homebrew is designed to work without using sudo. You can decide to use it but we strongly recommend not to do so. If you have used sudo and run into a bug then it is likely to be the cause. Please don’t file a bug report unless you can reproduce it after reinstalling Homebrew from scratch without using sudo.

You should only ever sudo a tool you trust. Of course, you can trust Homebrew ;) But do you trust the multi-megabyte Makefile that Homebrew runs? Developers often understand C++ far better than they understand make syntax. It’s too high a risk to sudo such stuff. It could break your base system, or alter it subtly.

And indeed, we’ve seen some build scripts try to modify /usr even when the prefix was specified as something else entirely.

Did you chown root /Applications/TextMate.app? Probably not. So is it that important to chown root wget?

If you need to run Homebrew in a multi-user environment, consider creating a separate user account especially for use of Homebrew.

Why isn’t a particular command documented?

If it’s not in man brew, it’s probably an external command. These are documented here.

Why haven’t you pulled my pull request?

If it’s been a while, bump it with a “bump” comment. Sometimes we miss requests and there are plenty of them. Maybe we were thinking on something. It will encourage consideration. In the meantime if you could rebase the pull request so that it can be cherry-picked more easily we will love you for a long time.

Can I edit formulae myself?

Yes! It’s easy! Just brew edit $FORMULA. You don’t have to submit modifications back toHomebrew/homebrew, just edit the formula as you personally need it and brew install. As a bonus brew update will merge your changes with upstream so you can still keep the formula up-to-date with your personal modifications!

Can I make new formulae?

Yes! It’s easy! Just brew create URL Homebrew will then open the formula in $EDITOR so you can edit it, but it probably already installs; try it: brew install $FORMULA. If you come up with any issues, run the command with the -d switch like so: brew install -d $FORMULA, which drops you into a debugging shell.

If you want your new formula to be part of Homebrew/homebrew or want to learn more about writing formulae, then please read the Formula Cookbook.

Can I install my own stuff to /usr/local?

Yes, brew is designed to not get in your way so you can use it how you like.

Install your own stuff, but be aware that if you install common libraries, like libexpat yourself, it may cause trouble when trying to build certain Homebrew formula. As a result brew doctor will warn you about this.

Thus it’s probably better to install your own stuff to the Cellar and then brew link it. Like so:

$ cd foo-0.1
$ brew diy
./configure —prefix=/usr/local/Cellar/foo/0.1
$ ./configure —prefix=/usr/local/Cellar/foo/0.1
[snip]
$ make && make install
$ brew link foo
Linking /usr/local/Cellar/foo/0.1… 17 symlinks created

Where was a formula deleted?

Use brew log $FORMULA to find out!

Sometimes formulae are moved to specialized repositories. These are the likely candidates:

• homebrew/dupes
• homebrew/games
• homebrew/versions

You can use brew tap to access these formulae:

brew tap homebrew/games
brew install …

Note that brew search still finds formula in taps.

Homebrew is a poor name, it is generic, why was it chosen?

@mxcl was too concerned with the beer theme and didn’t consider that the project may actually prove popular. By the time he realized it was too late. However, today, the first google hit for “homebrew” is not beer related ;-)

What does keg-only mean?

It means the formula is installed only into the Cellar; it is not linked into /usr/local. This means most tools will not find it. We don’t do this for stupid reasons. You can still link in the formula if you need to with brew link.

How can I specify different configure arguments for a formula?

brew edit $FORMULA and edit the formula. Currently there is no other way to do this.