message: Always built new states even if no children
  Could be going to an empty stack?!
diff: @@ -18,7 +18,6 @@ const Stack = ({ children, ...props }) => {
  newStatesLookup[name] = true;
  return { newStates, newStatesLookup };
  }, { newStates: [], newStatesLookup: {} })
  - if (newStates.length) {
  for(const oldState of oldStates) {
  if (!newStatesLookup[oldState.key])
  newStates.push({ ...oldState, __deleted: true });
  @@ -30,12 +29,10 @@ const Stack = ({ children, ...props }) => {
  const { state, crumbs } = stateNavigator.parseLink(url);
  changed = state.__deleted || crumbs.filter(({ state }) => state.__deleted).length;
  }
  - if (changed)
  + if (changed && newStates.length)
  stateNavigator.navigate(newStates[0].key);
  stateNavigator.onBeforeNavigate(validateNavigation);
  return newStates;
  - }
  - return oldStates;
  });
  return () => stateNavigator.offBeforeNavigate(validateNavigation);
  }, [ children ]);
  