with_retries.rb

 def with_retries(timeout = 5.seconds, retry_delay: 0.1.seconds, &blk)
    start = Time.now
    begin
      blk.call
    rescue
      if Time.now > start + timeout
        raise
      else
        sleep retry_delay
        retry
      end
    end
  end

I'd use Timeout rather than manually inspecting time, plus yield is a slight performance increase over the block itself.

def with_retries(timeout = 5.seconds, retry_delay: 0.1.seconds)
  Timeout::timeout(timeout) do
    begin
      yield
    rescue RSpec::Expectations::ExpectationNotMetError
      sleep retry_delay
      retry
    end
  rescue Timeout::Error
    yield
  end
end