Thread Sanitizer没有显示Xcode 8中的所有问题

Question

Thread Sanitizer不会显示所有问题。例如

  private func observeConversationUsers(_ isObserve: Bool, conversationID: String, updated: (() -> Void)?, fail: ((_ error: Error) -> Void)?) {
        guard isObserveConversationUsers != isObserve else { return }
        isObserveConversationUsers = isObserve

        DispatchQueue.global(qos: .background).async {
            let conversationUserRef = Database.database().reference().child(MainGateways.chat.description).child(MainGateways.conversationUsers.description).child(conversationID)


            if !isObserve {
                conversationUserRef.removeAllObservers()
                return
            }

            if !self.references.contains(conversationUserRef) { // for example this issue 
                self.references.append(conversationUserRef)
            }

            conversationUserRef.observe(.childAdded, with: { (snap) in
                if snap.value is NSNull {
                    return
                }
                guard let dict = snap.value as? [String : Any] else { return }
                guard let chatUserActivityModel = Mapper<ChatUserActivityModel>().map(JSON: dict) else { return }
                self.downloadImageProfile(chatUserActivityModel.userID, conversationID: conversationID)
            }, withCancel: { (error) in
                // TODO: - it
            })

            conversationUserRef.observe(.childRemoved, with: { (snap) in

            }, withCancel: { (error) in
                // TODO: - it
            })
        }
    }

我的诊断设置

我该如何解决？

更新：我做了一个非常简单的例子，但是Xcode在这里没有显示错误，尽管在另一个线程中调用了isPushSettingsFormVC属性

class MainTabBarController: UITabBarController {

    var isPushSettingsFormVC = false


    override func viewDidLoad() {
        super.viewDidLoad()
        // I think here is a data race
        DispatchQueue.global(qos: .background).async { [weak self] in
            self?.isPushSettingsFormVC = false
        }
    }

}