java.lang.AbstractMethodError: Receiver class com.google.api.gax.grpc.InstantiatingGrpcChannelProvider does not define or inherit an implementation of the resolved method 'abstract com.google.api.gax.rpc.TransportChannelProvider withExecutor(java.util.concurrent.Executor)' of interface com.google.api.gax.rpc.TransportChannelProvider.

Using com.google.firebase:firebase-admin:6.14.0 in a simple app fetching a single document by ID in Firestore, I am getting the following runtime exception:

Caused by: java.lang.AbstractMethodError: Receiver class com.google.api.gax.grpc.InstantiatingGrpcChannelProvider does not define or inherit an implementation of the resolved method ‘abstract com.google.api.gax.rpc.TransportChannelProvider withExecutor(java.util.concurrent.Executor)’ of interface com.google.api.gax.rpc.TransportChannelProvider.

I authenticated using end-user credentials from Google Cloud SDK. There is no Firebase or Google dependency other than firebase-admin. My OS is Fedora 32.

It seems the problem comes from the version of gax-grpc that is retrieved by firebase-admin since forcing Gradle to use the latest version resolves the problem:

implementation 'com.google.api:gax-grpc:1.57.0'

[BenWhitehead]

@lpellegr I spoke with some colleagues today and have some more detail for you.

Since your app has a direct dependency on google-cloud-core the recommendation from the GCP Java OSS team is to try using the libraries-bom for version resolution. This provides the benefit that a release of libraries-bom ensures all dependencies defined in it are binary compatible across the full dependency graph for all of the included projects (including grpc, guava, google-cloud-* and more. See The Google Cloud Platform Libraries BOM for links to all libraries) client libraries.

The version of libraries-bom which corresponds with the versions of google-cloud-firestore and google-cloud-storage used by firebase-admin is 6.0.0.

You can try out using the bom in your gradle project by updating your config as follows:

dependencies {
  implementation platform('com.google.cloud:libraries-bom:6.0.0')
  implementation 'com.google.cloud:google-cloud-core'
  implementation 'com.google.firebase:firebase-admin:6.14.0' 
}

@hiranya911 Do you think it would probably be beneficial to update firestore-admin to itself use libraries-bom. Does this sounds like a good idea to you? Should I create a new issue?

[lpellegr]

@BenWhitehead Thanks for the clear explanation and help.