}

	var wg sync.WaitGroup
	wg.Add(1)

	// Start the callback in a new green thread so that if we later fail
	// to switch the namespace back to the original one, we can safely
	// leave the thread locked to die without a risk of the current thread
	// left lingering with incorrect namespace.
	var innerError error
	go func() {
		defer wg.Done()
		runtime.LockOSThread()
		innerError = containedCall()
	}()
	wg.Wait()