check_that_user_bin_dir_is_in_path

# File lib/rubygems/installer.rb, line 598
  def check_that_user_bin_dir_is_in_path
    user_bin_dir = @bin_dir || Gem.bindir(gem_home)
    user_bin_dir = user_bin_dir.gsub(File::SEPARATOR, File::ALT_SEPARATOR) if
      File::ALT_SEPARATOR

    path = ENV['PATH']
    if Gem.win_platform? then
      path = path.downcase
      user_bin_dir = user_bin_dir.downcase
    end

    unless path.split(File::PATH_SEPARATOR).include? user_bin_dir then
      unless self.class.path_warning then
        alert_warning "You don't have #{user_bin_dir} in your PATH,\n\t  gem executables will not run."
        self.class.path_warning = true
      end
    end
  end