kafka-go: WriteMessages blocks indefinitely without returning error

I have an application that writes to a Kafka broker. It is configured with most of the default configuration in place like so:

config := kafka.WriterConfig{
	Brokers: brokerlist,
	Topic:   topic,
}

w := kafka.NewWriter(config)

I’ve observed w.WriteMessages(ctx, msgs) block without any apparent reason. I’ve been looking at the code to understand the underlying implementation. In what cases would this function block forever? If any maintainers can help diagnose this with me, it would be greatly appreciated.