Support for the Ruby 2.4 series has ended. See here for reference.
# File rubygems/installer.rb, line 114 def extract_files destination_dir, pattern = '*' FileUtils.mkdir_p destination_dir spec.files.each do |file| file = File.join destination_dir, file next if File.exist? file FileUtils.mkdir_p File.dirname(file) File.open file, 'w' do |fp| fp.puts "# #{file}" end end end