brew install ruby 2.0

gistfile1.rb

require 'formula'

class Ruby < Formula
  homepage 'http://www.ruby-lang.org/en/'
  url 'http://ftp.ruby-lang.org/pub/ruby/2.0/ruby-2.0.0-p0.tar.bz2'
  sha256 'c680d392ccc4901c32067576f5b474ee186def2fcd3fcbfa485739168093295f'

  head 'http://svn.ruby-lang.org/repos/ruby/trunk/'

  env :std

  option :universal
  option 'with-suffix', 'Suffix commands with "20"'
  option 'with-doc', 'Install documentation'
  option 'with-tcltk', 'Install with Tcl/Tk support'

  if build.universal?
    depends_on 'autoconf' => :build
  elsif build.head?
    depends_on :autoconf
  end

  depends_on 'pkg-config' => :build
  depends_on 'readline'
  depends_on 'gdbm'
  depends_on 'libyaml'
  depends_on :x11 if build.include? 'with-tcltk'
  depends_on 'openssl'

  fails_with :llvm do
    build 2326
  end

  def install
    system "autoconf" if build.head?

    args = ["--prefix=#{prefix}",
            "--enable-shared"]

    args << "--program-suffix=20" if build.include? "with-suffix"
    args << "--with-arch=x86_64,i386" if build.universal?
    args << "--disable-tcltk-framework" <<  "--with-out-ext=tcl" <<  "--with-out-ext=tk" unless build.include? "with-tcltk"
    args << "--disable-install-doc" unless build.include? "with-doc"
    args << "--with-openssl-dir=`brew --prefix openssl`"

    # Put gem, site and vendor folders in the HOMEBREW_PREFIX
    ruby_lib = HOMEBREW_PREFIX/"lib/ruby"
    (ruby_lib/'site_ruby').mkpath
    (ruby_lib/'vendor_ruby').mkpath
    (ruby_lib/'gems').mkpath

    (lib/'ruby').install_symlink ruby_lib/'site_ruby',
                                 ruby_lib/'vendor_ruby',
                                 ruby_lib/'gems'

    system "./configure", *args
    system "make"
    system "make install"
    system "make install-doc" if build.include? "with-doc"

  end

  def caveats; <<-EOS.undent
    NOTE: By default, gem installed binaries will be placed into:
      #{opt_prefix}/bin

    You may want to add this to your PATH.
    EOS
  end
end