anchor.diff:  
   require 'formula'
   require 'fileutils'
  +
  +BREWGEM_RUBYBINDIR = '<%= use_homebrew_ruby ? "#{homebrew_prefix}/bin" : "/usr/bin" %>'
  +BREWGEM_GEM_PATH = "#{BREWGEM_RUBYBINDIR}/gem"
  +BREWGEM_RUBY_PATH = "#{BREWGEM_RUBYBINDIR}/ruby"
   
   class RubyGemsDownloadStrategy < AbstractDownloadStrategy
     def fetch
       ohai "Fetching <%= name %> from gem source"
       HOMEBREW_CACHE.cd do
         ENV['GEM_SPEC_CACHE'] = "#{HOMEBREW_CACHE}/gem_spec_cache"
  -      system "gem", "fetch", "<%= name %>", "--version", resource.version
  +      system BREWGEM_GEM_PATH, "fetch", "<%= name %>", "--version", resource.version
       end
     end
   
  
positive.code:       file = Pathname.new("#{brew_gem_prefix}/#{gemspec.bindir}/#{exe}")
        (bin+file.basename).open('w') do |f|
          f << <<-RUBY
  #!#{ruby_path} --disable-gems
  ENV['GEM_HOME']="#{prefix}"
  ENV['GEM_PATH']="#{prefix}"
  require 'rubygems'
  
negative.code:     ENV['GEM_HOME']="#{prefix}"
      ENV['GEM_PATH']="#{prefix}"
  
      system BREWGEM_GEM_PATH, "install", cached_download,
               "--no-ri",
               "--no-rdoc",
               "--no-wrapper",
  