Required files
rbconfig
rubygems/rubygems_version.rb
thread
rubygems/user_interaction
rubygems/builder
rubygems/format
rubygems/remote_installer
rubygems/installer
rubygems/validator
rubygems/doc_manager
rubygems/cmd_manager
rubygems/gem_runner
rubygems/config_file
fileutils
rbconfig/datadir
rubygems/source_index
rubygems/specification
rubygems/security
rubygems/version
rubygems/custom_require