message: remove ErrorDetected variant from ProbeState
diff: @@ -176,8 +176,7 @@ where
  /// Return value of `probe` helper.
  enum ProbeState<V, G> {
  - UpToDate(V),
  - CycleDetected,
  + UpToDate(Result<V, CycleDetected>),
  StaleOrAbsent(G),
  }
  @@ -208,8 +207,7 @@ where
  // First, do a check with a read-lock.
  match self.probe(self.map.read(), runtime, revision_now, descriptor, key) {
  - ProbeState::UpToDate(v) => return Ok(v),
  - ProbeState::CycleDetected => return Err(CycleDetected),
  + ProbeState::UpToDate(v) => return v,
  ProbeState::StaleOrAbsent(_guard) => (),
  }
  @@ -239,8 +237,7 @@ where
  descriptor,
  key,
  ) {
  - ProbeState::UpToDate(v) => return Ok(v),
  - ProbeState::CycleDetected => return Err(CycleDetected),
  + ProbeState::UpToDate(v) => return v,
  ProbeState::StaleOrAbsent(map) => {
  let mut map = RwLockUpgradableReadGuard::upgrade(map);
  map.insert(key.clone(), QueryState::in_progress(runtime.id()))
  @@ -362,10 +359,10 @@ where
  Some(QueryState::InProgress { id, waiting }) => {
  let other_id = *id;
  if other_id == runtime.id() {
  - return ProbeState::CycleDetected;
  + return ProbeState::UpToDate(Err(CycleDetected));
  } else {
  if !runtime.try_block_on(descriptor, other_id) {
  - return ProbeState::CycleDetected;
  + return ProbeState::UpToDate(Err(CycleDetected));
  }
  let (tx, rx) = mpsc::channel();
  @@ -379,7 +376,7 @@ where
  std::mem::drop(map);
  let value = rx.recv().unwrap();
  - return ProbeState::UpToDate(value);
  + return ProbeState::UpToDate(Ok(value));
  }
  }
  @@ -402,10 +399,10 @@ where
  key,
  memo.changed_at,
  );
  - return ProbeState::UpToDate(StampedValue {
  + return ProbeState::UpToDate(Ok(StampedValue {
  value: value.clone(),
  changed_at: memo.changed_at,
  - });
  + }));
  }
  }
  }
  