class Gem::DependencyInstaller

def in_background(what) # :nodoc:
  fork_happened = false
  if @build_docs_in_background && Process.respond_to?(:fork)
    begin
      Process.fork do
        yield
      end
      fork_happened = true
      say "#{what} in a background process."
    rescue NotImplementedError
    end
  end
  yield unless fork_happened
end