Installing Ruby, Rubygems, Rails, and Mongrel on Mac OS X 10.5 (Leopard)

These are instructions for compiling and installing Ruby, Rubygems, Ruby on Rails, and Mongrel on Mac OS X 10.5 (Leopard).
If you already know why I write these tutorials, if you already have /usr/local in your path, if you’ve installed XCode installed already … in other words, if you’re an old-school Hivelogic reader, just click here to jump right to the instructions.

The FAQ (Sort Of)

Below I’ll walk you through getting your system ready for building and compiling open source software. But before I do, please allow me to answer of few of the questions I invariably get asked every time I release this type of do-it-yourself tutorials:
Why would I want to compile this stuff when it ships as part of Leopard?
Good question! Leopard ships with Ruby 1.8.6 and Rails 1.2.3 – both respectably recent and stable versions. And it’s easy enough to update to the latest version of Rails with a single command (sudo gem install rails if you’re curious).
Then why roll your own? I expand on the benefits of building your own open source utilities (like Ruby and Rails) and why where they live is important in my article entitled Using /usr/local, but here are a few of the reasons:
  1. You want to run the latest/greatest versions of available software and don’t want to wait (or hope) for Apple to release an update.
  2. Your want to update, tweak, and customize your own tools while keeping your system “stock” from Apple’s standpoint.
  3. Apple may decide to modify these utilities during a system update, and doing so may break your stuff.
  4. You can move or remove the /usr/local filesystem, or even transfer it to another machine in one step.
  5. You’re used to, interested in, or curious about in the compile and build process.
For some people, these reasons are enough to take a few minutes to build your own software.
Why wouldn’t I just use MacPorts or Fink?
Both MacPorts and Fink are great projects, and I wholeheartedly support their efforts. I’m also a longtime FreeBSD geek, and the FreeBSD ports tree is something I’ve relied upon for ages. So I really get what MacPorts and Fink are about.
On the other hand, I’m a geek at heart, I don’t mind compiling my own software, and I like the ability to build just what I need, right when I need it, without installing or waiting for any additional or externally-maintained software. If this method sounds like a headache to you, I know where you’re coming from. MacPorts and Fink provide most excellent alternatives. Tell them I sent you.
I used your instructions and I got the following error …
Please don’t email me about it but instead, post your question in the comments. I try and read and respond as often as I can. When I can’t, other Hivelogic readers often step in and try to help (they’re a great bunch), and usually we can figure it out together.


You will need:
  1. Mac OS X 10.5 (Leopard)
  2. Xcode 3.0 or newer
  3. Familiarity with (or willingness to use) the Mac OS X Terminal application
Note: You will probably need to install Xcode from the Mac OS X install DVD/CD (in the Optional Installs -> Xcode folder). You can also download it from Apple’s Developer Connection free of charge.
Another Note: These instructions are written for people using the default Mac OS X shell, bash. If you haven’t manually changed your shell from bash, and you didn’t upgrade to Leopard from something older than Tiger, then you don’t have anything to worry about. If you’ve taken specific steps to change the default shell to something other than bash (like tcsh), then you’ll need to figure out equivalent syntax to use when setting paths and environment variables, or just switch back to bash, because we just roll with bash here. Sorry.

Just In Case

While it’s unlikely that any of these steps might damage your system somehow, it’s probably a good idea to have a current backup of everything, just in case (I recommend SuperDuper! for this by the way, awesome product). So you’re following these instructions at your own risk, and I’m not liable for anything that happens.

A Note about sudo

With great power comes great responsibility, so Mac OS X may prompt you for your password prior to executing some of the commands you’ll be typing. It may do this only once, or several times throughout this process. Just re-enter your password as needed.

Using Terminal

You’ll need to launch the Terminal application. It can be found in the /Applications/Utilities folder.
Each of the lines below appearing in monospaced type should be entered into Terminal, and be followed by the Return key.


Don’t skip this step!
Mac OS X, like other UNIX systems, uses something called a path to determine where it should look for applications on the command line (that is, when you’re using the Terminal app). The path is actually an environment variable, set by a special file that’s automatically executed when you open a new Terminal window.
We need to make sure that our path is set to look for files in /usr/local (the place where we’ll be installing the tools) before looking anywhere else. This is important.
To see if the path has been set properly, we can check the contents of the .bash_login file (the special file hidden in our home folder) for a PATH line using a text editor. TextMate, TextWrangler, BBEdit, and vi are all perfectly good options. To open the file with TextMate, for example, we can type:
mate ~/.bash_login
This will open the file if it already exists, or open a blank file if it doesn’t. Add the following line at the very end of the file:
export PATH="/usr/local/bin:/usr/local/sbin:/usr/local/mysql/bin:$PATH" 
Now save and close the file.
It doesn’t matter how many other lines there are in the file, or what they say or do. Just make sure that this line comes last and you should be fine.
To make sure the changes are picked up correctly, we now need to execute the file with the following command:
. ~/.bash_login
It’s likely there will be no response from the shell here, just the prompt, but that’s OK, the changes have been picked up and we’re ready to move on.
You can also close your Terminal and open a new one instead if you’d like.
Note: You may have noticed that I’ve added MySQL to the path in the line above. That’s because most users will be installing MySQL later in this tutorial. If you’re the type to want to use something like SQLite or PostGreSQL as your database instead of MySQL, you can feel free to omit the /usr/local/mysql/bin: bit from the line above, and replace it with the path to the database of your choice. If this note doesn’t make sense to you, even if you don’t plan to install MySQL later, just keep on going … the extra bit in the path statement won’t affect you at all.

Setting Up

I like to create a folder to contain all of the downloaded files and their respective build folders. I tend to keep this folder around indefinitely. Source code doesn’t take up much space, and it’s useful to refer back to later to remind yourself of previous installation details or techniques, installed versions, for a fast install at a later time, or in case you want to uninstall something.
For these examples, we’ll create a folder called src in the /usr/local section of the filesystem, and change directories into that folder. It will be our workspace for everything we do here:
sudo mkdir -p /usr/local/src
sudo chgrp admin /usr/local/src
sudo chmod -R 775 /usr/local/src
cd /usr/local/src
You’ll download and compile everything in this new folder.


Ok, let’s get started. Unlike previous versions of Mac OS X, Leopard has everything you’ll need to compile Ruby. You don’t need to install any prerequisites. Take these commands and type or paste them into Terminal:
curl -O [url][/url]
tar xzvf ruby-1.8.6-p111.tar.gz
cd ruby-1.8.6-p111
./configure --enable-shared --enable-pthread CFLAGS=-D_XOPEN_SOURCE=1
sudo make install
cd ..
To verify that Ruby is installed and in your path, just type:
which ruby
You should see:
If you don’t, you haven’t set your path correctly.


With Ruby installed, we can move on to RubyGems. Same routine:
curl -O [url][/url]
tar xzvf rubygems-1.0.1.tgz
cd rubygems-1.0.1
sudo /usr/local/bin/ruby setup.rb
cd ..

Ruby on Rails

At last, we’re ready to install Rails. RubyGems will handle this for us:
sudo gem install rails
Mongrel and Capistrano get installed the same way:
sudo gem install mongrel
sudo gem install capistrano
There are a handful of other gems you’ll undoubtedly want, and you can install them one at a time, or all on one line (if you have a list) like this:
sudo gem install RedCloth termios rspec sake

The MySQL Gem

As of Rails 2.0, the default database system is is now SQLite, which also ships with Leopard.
Many of us still run MySQL locally though, and want to install the MySQL gem for better Rails integration. If you followed my MySQL for Mac OS X installation instructions or used one of the official MySQL distributions, your MySQL lives in /usr/local/mysql. You can install the gem using the following command:
sudo gem install mysql -- --with-mysql-dir=/usr/local/mysql

We’re Done

Congratulations, you now have a custom-built, properly installed Ruby on Rails system! You might also like to build your own Subversion client or run your own MySQL server too.