class Gem::BasicSpecification

def contains_requirable_file?(file)
  if ignored?
    if platform == Gem::Platform::RUBY || Gem::Platform.local === platform
      warn "Ignoring #{full_name} because its extensions are not built. " \
           "Try: gem pristine #{name} --version #{version}"
    end
    return false
  end
  is_soext = file.end_with?(".so", ".o")
  if is_soext
    have_file? file.delete_suffix(File.extname(file)), Gem.dynamic_library_suffixes
  else
    have_file? file, Gem.suffixes
  end
end