I’ll introduce the steps to set up a Ruby development environment using the Ruby version management tool RVM on Mac OS Lion with Xcode 4.1. 　

apple-gcc42 のインストール / Installing apple-gcc42

(Skip this section if you’re using Xcode 4.1 or earlier)

■ Method 1

First, if you’re using Xcode 4.2, the supported gcc has changed, so install apple-gcc42 that was previously included.

・[Mac] Homebrew で apple-gcc42 をインストールする方法 | CodeNote.net

If you haven’t installed Homebrew, please refer to this:

・[Mac] Homebrew をインストール | CodeNote.net 　

■ Method 2

Use OSX GCC Installer.

・kennethreitz/osx-gcc-installer 　

RVMのインストール / Installing RVM

Install the Ruby version management tool RVM.

$ bash -s stable < <(curl -s https://raw.github.com/wayneeseguin/rvm/master/binscripts/rvm-installer)

Next, add configuration to ~/.bash_profile.

If it’s already created and has settings written, you don’t need to do anything special.

$ echo '[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load RVM function' >> ~/.bash_profile

After configuration, reload .bash_profile.

$ source ~/.bash_profile

　

Readlineなどの必要なライブラリーのインストール / Installing Required Libraries like Readline

Install libraries as needed.

Before installing with the rvm command, temporarily change environment variables.

export ARCHFLAGS="-arch x86_64"
export CC='gcc-4.2'

At minimum, install readline, and install others as needed.

rvm pkg install readline
rvm pkg install iconv
rvm pkg install zlib
rvm pkg install openssl

　

Rubyをバージョン指定してインストール / Installing Ruby with Version Specification

Install stable versions of Ruby 1.9.3, 1.9.2, and 1.8.7.

rvm install 1.9.3
rvm install 1.9.2
rvm install 1.8.7

Verify that each was installed successfully.

$ rvm list
rvm rubies

   ruby-1.8.7-p357 [ i686 ]
   ruby-1.9.2-p290 [ x86_64 ]
   ruby-1.9.3-p0 [ x86_64 ]

# Default ruby not set. Try 'rvm alias create default '.

# => - current
# =* - current && default
#  * - default

　

デフォルトの Ruby のバージョンを設定 / Setting Default Ruby Version

Finally, specify the Ruby version to use by default.

This time, I’ll set Ruby 1.9.3 as the default.

$ rvm use 1.9.3 --default
Using /Users/your_username/.rvm/gems/ruby-1.9.3-p0

Verify that it was set correctly.

$ ruby -v
ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-darwin11.3.0]

$ rvm list

rvm rubies

   ruby-1.8.7-p357 [ i686 ]
   ruby-1.9.2-p290 [ x86_64 ]
=* ruby-1.9.3-p0 [ x86_64 ]

# => - current
# =* - current && default
#  * - default

That’s all from the Gemba regarding setting up Ruby development environment with RVM.