使用 firestore 时找不到满足版本限制的“com.google.code.gson:gson”版本

Question

It does not occurred when remove implementation 'com.google.firebase:firebase-firestore:21.3.0' dependency in my gradle and It causes only when to test not to run app .

here is the full error message

Cannot find a version of 'com.google.code.gson:gson' that satisfies the version constraints: 
   Dependency path 'myapp:app:unspecified' --> 'androidx.room:room-testing:2.2.1' --> 'androidx.room:room-migration:2.2.1' --> 'com.google.code.gson:gson:2.8.0'
   Constraint path 'myapp:app:unspecified' --> 'com.google.code.gson:gson:{strictly 2.7}' because of the following reason: debugRuntimeClasspath uses version 2.7
   Dependency path 'myapp:app:unspecified' --> 'com.google.firebase:firebase-firestore:21.3.0' --> 'io.grpc:grpc-android:1.21.0' --> 'io.grpc:grpc-core:1.21.0' --> 'com.google.code.gson:gson:2.7'

What should I do?

Answer 1

First of all, you can always check your dependencies tree like this: gradlew app:dependencies (that's assuming your module in question is called app; for linux you will likely have to call it like this ./gradlew app:dependencies )

That said, your log seems to contain all you need already: room is using 2.8.0 and firebase is using 2.7. Please try to exclude gson transitive dependency, say, from room ( exclude group: 'com.google.code.gson' ) and let's see if that helps.