Setting up a Ruby development laptop on Mountain Lion

I've just reinstalled my MacBook Pro with Mountain Lion, and I always start from scratch instead of doing an update, as I don't want to bring along old cruft - and it is a good way to make sure I don't bring infected/trojaned files (if there were any).

Here are the the (very terse) steps I took to get my Ruby development environment back up, more a reminder to myself than a installation cookbook, but I'm sure it will be helpful for someone...

Install Mountain Lion

Duh!

Install XCode

Available in the App Store, also make sure to install the command line tools.

Install rbenv

There is a chicken and egg problem here: to install rbenv you need git to clone the repo, and to install git you need homebrew, and to install homebrew you need ruby. So work around that, pull down a tar-ball of the rbenv first.

cd ~
mkdir tmp
cd tmp
wget https://github.com/sstephenson/rbenv/tarball/master
tar xf master
mv sstephenson-rbenv-* ~/.rbenv

Install Ruby

Add the following to ~/.gemrc to avoid generating ri & rdoc.

gem: --no-ri --no-rdoc

I use yard instead, which is much nicer!

Get the latest version of Ruby from http://www.ruby-lang.org/en/downloads/ (1.9.3-p194 at the time of writing)

cd ~/tmp
tar xzf ruby-1.9.3-p194.tar.gz
cd ruby-1.9.3-p194
./configure --prefix $HOME/.rbenv/versions/1.9.3-p194
make
make install

Also do the normal rbenv in your .bash_profile

Install homebrew

Now that ruby is available, homebrew can be installed

ruby <(curl -fsSkL raw.github.com/mxcl/homebrew/go)

Install git

brew install git

Install libyaml

brew install libyaml

Reinstall rbenv & Ruby

Now we have all pieces to install rbenv for real

cd ~
rm -rf .rbenv
git clone git://github.com/sstephenson/rbenv.git .rbenv
cd ~/tmp/ruby-1.9.3-p194
make distclean
./configure --prefix $HOME/.rbenv/versions/1.9.3-p194
make
make install

Install X11

Mountain Lion doesn't come with X11 headers any more, and if you try to compile Ruby 1.8 it requires X11 for tcl/tk, so it will fail with:

/usr/include/tk.h:78:23: error: X11/Xlib.h: No such file or directory

You can get X11 from http://xquartz.macosforge.org/landing/
After that you need to set

export CPPFLAGS=-I/opt/X11/include

Install Ruby 1.8

If you don't need tcl/tk & X11 in Ruby 1.8 you can just supply the flags

--disable-tcl --disable-tk

to your configure command, but if you do, you are now ready to compile 1.8

./configure --prefix $HOME/.rbenv/versions/1.8.7-p370

Done!

After this you are done!

martin@mbp[master]$ rbenv versions
  1.8.7-p370
  1.9.2-p320
* 1.9.3-p194 (set by /Users/martin/.rbenv/version)

Happy Ruby hacking :)