Client fails to initialize when enabling DirectPath

[sushanb]

Impacted Gax Version: 2.39.0
Impacted Libraries: Storage, Spanner, BigTable

If you have DirectPath enabled in your client via the TransportChannelProvider settings:

InstantiatingGrpcChannelProvider.newBuilder().setAttemptDirectPath(true).setAttemptDirectPathXds().build();

You may see the client fail to initialize via a Null Pointer Exception.

Resolution

Please skip Gax v2.39.0 and use v2.40.0+.