Produce on an inexistent partition errors only the second time

[martanit]

To reproduce:

producer←⎕NEW Producer     
producer.configure'bootstrap.servers' 'localhost:9092' 
producer.configure'client.id' 'martina'    

The produce a record on an inexistent partition:

producer.produce_record ⎕NEW #.Record('animals' 'Blackbird' 'key01' 100)   
0 5

the first time, the program returns 0 while, on a second attempt,

producer.produce_record ⎕NEW #.Record('animals' 'Blackbird' 'key01' 100)   
¯190 6

an error is produced (¯190 is RD_KAFKA_RESP_ERR__UNKNOWN_PARTITION).