module Gem

  class << self
    SYSTEM_DIR = File.join(RbConfig::CONFIG['rubylibprefix'], 'gems', RbConfig::CONFIG['ruby_version'])

    remove_method :install_extension_in_lib
    def install_extension_in_lib
      false
    end

    remove_method :default_dir
    def default_dir
      user_dir
    end

    remove_method :default_bindir
    def default_bindir
      File.join(default_dir, 'bin')
    end

    remove_method :default_specifications_dir
    def default_specifications_dir
      File.join(SYSTEM_DIR, 'specifications', 'default')
    end

    remove_method :default_path
    def default_path
      path = []
      path << user_dir if user_home and File.exist?(user_home)
      path << SYSTEM_DIR
      path << vendor_dir if vendor_dir and File.directory?(vendor_dir)
      path
    end

  end

end