SessionManager is "Publishing changes from background thread"

[mattcorey]

Hi - with SDK versions 2.10.0 and 2.11.0, I'm getting a bunch of these errors both from Xcode 26.1.1, and from the Console app (when running in TestFlight):

Publishing changes from background threads is not allowed; make sure to publish values from the main thread (via operators like receive(on:)) on model updates.

These are accompanied by the dreaded 'purple warning' in Xcode.

These warnings seem to occur roughly once/second, and Xcode is pointing me to the following lines:

private var deletedSessionsCount: Int {
        get { TelemetryDeck.customDefaults?.integer(forKey: Self.deletedSessionsCountKey) ?? 0 }
        set {
            self.persistenceQueue.async {
                TelemetryDeck.customDefaults?.set(newValue, forKey: Self.deletedSessionsCountKey).  <-- Here (line 53)
            }
        }
    }

        self.persistenceQueue.async {
            if let updatedSessionData = try? Self.encoder.encode(self.recentSessions) {
                TelemetryDeck.customDefaults?.set(updatedSessionData, forKey: Self.recentSessionsKey) <-- Here (line 197)
            }
        }

[mattcorey]

Found this issue - it was my app listening for UserDefaults.didChangeNotification, but not pinning it to the main thread. SessionManager happens to update UserDefaults regularly, and this handler was being triggered from whatever thread the update occurred on (even though it's a separate instance of UserDefaults).

Closing - sorry if this wasted too much time!

[kkostov]

Thanks for the feedback @mattcorey - we're working on a new version of the SDK that will make all this a lot easier to deal with. Happy to hear you found a solution 🤩 !