// not as optimal but at least always safe to do.
				runtime.UnlockOSThread()
			}
		}()

		return toRun()
	}

	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.