class Bundler::RubygemsIntegration::MoreFuture

def backport_ext_builder_monitor
  require "rubygems/ext"
  Gem::Ext::Builder.class_eval do
    unless const_defined?(:CHDIR_MONITOR)
      const_set(:CHDIR_MONITOR, EXT_LOCK)
    end
    remove_const(:CHDIR_MUTEX) if const_defined?(:CHDIR_MUTEX)
    const_set(:CHDIR_MUTEX, const_get(:CHDIR_MONITOR))
  end
end