install_from_gemdeps

# File lib/rubygems/request_set.rb, line 199
  def install_from_gemdeps options, &block
    gemdeps = options[:gemdeps]

    @install_dir = options[:install_dir] || Gem.dir
    @prerelease  = options[:prerelease]
    @remote      = options[:domain] != :local
    @conservative = true if options[:conservative]

    gem_deps_api = load_gemdeps gemdeps, options[:without_groups], true

    resolve

    if options[:explain]
      puts "Gems to install:"

      sorted_requests.each do |spec|
        puts "  #{spec.full_name}"
      end

      if Gem.configuration.really_verbose
        @resolver.stats.display
      end
    else
      installed = install options, &block

      if options.fetch :lock, true then
        lockfile =
          Gem::RequestSet::Lockfile.new self, gemdeps, gem_deps_api.dependencies
        lockfile.write
      end

      installed
    end
  end