Udacity Firebase教程添加Firebase UI Auth依赖后Gradle构建失败求助

Hey there! Let's work through this Gradle build issue you ran into after adding the FirebaseUI Auth dependency. This is almost always a version compatibility problem—older FirebaseUI releases require specific Firebase SDK versions to play nice together. Here's how to fix it step by step:

1. Align Firebase SDK Versions with FirebaseUI 3.2.2 #

FirebaseUI Auth 3.2.2 requires Firebase SDK version 11.8.0 for core services like Auth and Core. Make sure all your Firebase-related dependencies in your app-level build.gradle use this exact version. For example:

// App-level build.gradle
dependencies {
    // Match these versions to FirebaseUI 3.2.2
    implementation 'com.google.firebase:firebase-core:11.8.0'
    implementation 'com.google.firebase:firebase-auth:11.8.0'
    implementation 'com.firebaseui:firebase-ui-auth:3.2.2'
    // Your other project dependencies...
}

2. Update Google Services Plugin (Project-level) #

You'll also need to use the matching version of the Google Services plugin in your project-level build.gradle. For Firebase SDK 11.8.0, stick with version 3.2.1:

// Project-level build.gradle
buildscript {
    dependencies {
        classpath 'com.google.gms:google-services:3.2.1'
        // Other classpath dependencies...
    }
}

3. Clean & Rebuild Your Project #

Cached build files often cause weird conflicts. Try these steps to reset:

• Go to Build > Clean Project in Android Studio
• Then select Build > Rebuild Project
• If that doesn't work, manually delete the .gradle folder (in your project root) and build folders (in your app module), then re-sync your Gradle files.

4. Resolve Dependency Conflicts #

If errors persist, run this command in your terminal to check for conflicting dependencies:

./gradlew app:dependencies

Look for any libraries pulling in a different version of Firebase Auth/Core. You can exclude conflicting versions from the FirebaseUI dependency like this:

implementation('com.firebaseui:firebase-ui-auth:3.2.2') {
    exclude group: 'com.google.firebase', module: 'firebase-auth'
}

Just make sure you've already explicitly added the correct 11.8.0 version of firebase-auth as shown in step 1.

A quick heads-up: FirebaseUI 3.2.2 is pretty old. If your project allows, consider upgrading to a newer, supported version of FirebaseUI and Firebase SDKs to avoid future compatibility headaches.

内容的提问来源于stack exchange，提问作者Sweetie Anang