firebase-messaging: NoClassDefFoundError for AnalyticsConnector when firebase-measurement-connector is excluded

[davunderscorei]

[READ] Step 1: Are you in the right place? ✅

[REQUIRED] Step 2: Describe your environment

• Android Studio version: N/A
• Firebase Component: firebase-messaging
• Component version: 25.0.2

[REQUIRED] Step 3: Describe the problem

firebase-messaging calls MessagingAnalytics.logToScion() when the intent carries the "google.c.a.e=1" extra (Constants.AnalyticsKeys.ENABLED). logToScion() references AnalyticsConnector as a local variable type (despite the nearby TODO b/78465387) which causes a NoClassDefFoundError at method-invocation time on any build that excludes firebase-analytics. The SDK comment claims missing analytics is handled gracefully, but the class-load crash happens before any null-check can run.

Culprit code

Steps to reproduce:

1. Fully disable Firebase Measurement Connector as per this Stack Overflow answer. Most notably: exclude group: 'com.google.firebase', module: 'firebase-measurement-connector' [edit: corrected from Firebase Analytics -> Firebase Measurement Connector]
2. Send a test Firebase message whilst target app is open
3. Observe crash:

FATAL EXCEPTION: Firebase-Messaging-Intent-Handle
java.lang.NoClassDefFoundError: Failed resolution of: Lcom/google/firebase/analytics/connector/AnalyticsConnector;
	at com.google.firebase.messaging.MessagingAnalytics.logToScion(MessagingAnalytics.java:313)
	at com.google.firebase.messaging.MessagingAnalytics.logNotificationReceived(MessagingAnalytics.java:80)
	at com.google.firebase.messaging.FirebaseMessagingService.passMessageIntentToSdk(FirebaseMessagingService.java:202)
	at com.google.firebase.messaging.FirebaseMessagingService.handleMessageIntent(FirebaseMessagingService.java:190)
	at com.google.firebase.messaging.FirebaseMessagingService.handleIntent(FirebaseMessagingService.java:179)
	at com.google.firebase.messaging.EnhancedIntentService.lambda$processIntent$0$com-google-firebase-messaging-EnhancedIntentService(EnhancedIntentService.java:82)
	at com.google.firebase.messaging.EnhancedIntentService$$ExternalSyntheticLambda1.run(D8$$SyntheticClass:0)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1100)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at com.google.android.gms.common.util.concurrent.zza.run(com.google.android.gms:play-services-basement@@18.3.0:2)

Workaround

Stripping the extra by overriding handleIntent in a custom FirebaseMessagingService prevents shouldUploadScionMetrics() from returning true, so logToScion() is never entered and AnalyticsConnector is never loaded.

class MyFcmService : FirebaseMessagingService() {
    override fun handleIntent(intent: Intent) {
        intent.removeExtra("google.c.a.e")
        super.handleIntent(intent)
    }
}

[lehcar09]

Hi @davunderscorei, thank you for reaching out and raising this. I was able to reproduce the issue on my end.

As you noted, this error is expected because the Analytics component was excluded during the build process. I checked the internal bug report (b/78465387) mentioned in the comment; unfortunately, there hasn't been any movement on it. I will follow up with our engineering team to get an update.

In the meantime, could you share a bit more context on why you are explicitly excluding the Firebase Analytics dependency? If you aren't using Analytics, the standard approach is simply to omit it from your build dependencies entirely.

[google-oss-bot]

Hey @davunderscorei. We need more information to resolve this issue but there hasn't been an update in 5 weekdays. I'm marking the issue as stale and if there are no new updates in the next 5 days I will close it automatically.

If you have more information that will help us get to the bottom of this, just add a comment!

[davunderscorei]

Thanks for reproducing this, @lehcar09

Why we exclude it: a deliberate privacy/GDPR choice - our production builds ship with zero analytics by design. The linked Stack Overflow answer is the used recipe.

On the trigger - and apologies, my original post pointed at the wrong module: the failing class AnalyticsConnector actually ships in firebase-measurement-connector, which firebase-messaging declares as a direct compile dependency in its own POM. Excluding firebase-analytics alone wouldn't reproduce this - it's the connector being absent that does, and the "fully disable Analytics" recipes strip that module too. I'll update the issue accordingly.

On "just omit it": that's the catch - firebase-measurement-connector isn't something we add, it arrives transitively via firebase-messaging, so there's nothing to omit and exclude is the only lever. (We never pull in firebase-analytics itself at all.)

[lehcar09]

Thank you for the clarification @davunderscorei. I'll raise this to our engineers to see what we can do here. Thanks!