I reviewed the Pulsar code in question, it logs the exception directly before completing the future with it.

https://github.com/apache/pulsar/blob/e7fe8893bd559ea9db085d2dc7121ab04767fdfb/pulsar-client/src/main/java/org/apache/pulsar/client/impl/PulsarClientImpl.java#L768-L771

            consumerSubscribedFuture.thenRun(() -> readerFuture.complete(reader)).exceptionally(ex -> {
                log.warn("[{}] Failed to get create topic reader", topic, ex);
                readerFuture.completeExceptionally(ex);
                return null;

There's probably little you can do here.