class Bundler::Fetcher

def user_agent
  @user_agent ||= begin
    ruby = Bundler.ruby_version
    agent = "bundler/#{Bundler::VERSION}"
    agent += " rubygems/#{Gem::VERSION}"
    agent += " ruby/#{ruby.version}"
    agent += " (#{ruby.host})"
    agent += " command/#{ARGV.first}"
    if ruby.engine != "ruby"
      # engine_version raises on unknown engines
      engine_version = ruby.engine_version rescue "???"
      agent += " #{ruby.engine}/#{engine_version}"
    end
    # add a random ID so we can consolidate runs server-side
    agent << " " << SecureRandom.hex(8)
  end
end