Error reasons and codes

REST API

enum PreconditionError {
  // Not set.
  PRECONDITION_ERROR_UNSPECIFIED = 0;

  // Specifies that Service Networking was not enabled.
  SERVICE_NETWORKING_NOT_ENABLED = 1;

  // Specifies that Network is not peered with PSA producer network.
  NETWORK_NOT_PEERED = 2;

  // Private Service Access IP address range exhausted or does not exist.
  NETWORK_RANGES_NOT_AVAILABLE = 3;

  // Compute Engine API is not enabled for project.
  COMPUTE_ENGINE_NOT_ENABLED = 4;

  // Service account used by service networking does not have access.
  SERVICE_NETWORKING_PERMISSION_DENIED = 5;
}

gcloud