ROOT on OS X 10.11 El CapitanPublished on
The original post is below for posterity, but installing ROOT has been much simpler for a while now, whether you’re on El Capitan, Sierra, High Sierra, Mojave, Catalina, or Big Sur.
There are only two steps:
- Install Homebrew.
- Run this command:
$ brew install root
Boom. Just take care to read the information printed at the end. You can review it later if you missed it:
$ brew info root ==> Caveats Because ROOT depends on several installation-dependent environment variables to function properly, you should add the following commands to your shell initialization script (.bashrc/.profile/etc.), or call them directly before using ROOT. For bash users: . /usr/local/bin/thisroot.sh For zsh users: pushd /usr/local >/dev/null; . bin/thisroot.sh; popd >/dev/null For csh/tcsh users: source /usr/local/bin/thisroot.csh For fish users: . /usr/local/bin/thisroot.fish
I recommend installing ROOT via Anaconda as an alternative, which often integrates more nicely in to the reproducible analysis paradigm.
I’ve written some lengthy guides on installing ROOT, firstly for OS X 10.8 Mountain Lion and then for OS X 10.9 Mavericks.
They were long because the install process with CMake could be convoluted, requiring several dependencies that are occasionally non-obvious. These days, though, things are extremely simple.
Homebrew is a software management program for OS X. A large group of volunteers maintains a set of so-called formula, recipes that tell your Mac how to build pieces of software.
If you don’t already have Homebrew installed, I highly recommend it. It makes it extremely easy to install software and to keep it up-to-date. To install CMake, for example, you would do:
$ brew install cmake
In addition to the standard repository of formula, which includes formula for programs like CMake and git, there’s a repository dedicated to programs used for science, called Homebrew Science. This repository contains formula for ROOT 5 and ROOT 6.
brew only knows about the standard repository of formula, so
first add the Homebrew Science collection.
$ brew tap homebrew/science
Now we can install ROOT. We’ll go with ROOT 6 here, the latest version.
$ brew install root6
That was easy!
You’ll notice that Homebrew gives you some instructions after you’ve run the installation. You can look at these instructions whenever you like.
$ brew info root6
This tells you to add a line to your shell configuration.
For the Bash shell, you can add these lines to the
.bashrc file in your home directory:
. $(brew --prefix root6)/libexec/thisroot.sh
Open a new shell and try it out by running