install

# File lib/rubygems/request_set.rb, line 139
  def install options, &block # :yields: request, installer
    if dir = options[:install_dir]
      requests = install_into dir, false, options, &block
      return requests
    end

    cache_dir = options[:cache_dir] || Gem.dir
    @prerelease = options[:prerelease]

    requests = []

    sorted_requests.each do |req|
      if req.installed? then
        req.spec.spec.build_extensions

        if @always_install.none? { |spec| spec == req.spec.spec } then
          yield req, nil if block_given?
          next
        end
      end

      path = req.download cache_dir

      inst = Gem::Installer.new path, options

      yield req, inst if block_given?

      requests << inst.install
    end

    requests
  ensure
    raise if $!
    return requests if options[:gemdeps]

    specs = requests.map do |request|
      case request
      when Gem::Resolver::ActivationRequest then
        request.spec.spec
      else
        request
      end
    end

    require 'rubygems/dependency_installer'
    inst = Gem::DependencyInstaller.new options
    inst.installed_gems.replace specs

    Gem.done_installing_hooks.each do |hook|
      hook.call inst, specs
    end unless Gem.done_installing_hooks.empty?
  end