contains_requirable_file?

# File lib/rubygems/basic_specification.rb, line 68
  def contains_requirable_file? file
    if @ignored then
      return false
    elsif missing_extensions? then
      @ignored = true

      warn "Ignoring #{full_name} because its extensions are not built.  " +
        "Try: gem pristine #{name} --version #{version}"
      return false
    end

    have_file? file, Gem.suffixes
  end