pq: null value in column "username" violates not-null constraint

Hi guys,

Hope you are all well !

I run the following as per the README instructions (edited also /etc/hosts):

make run-twitter
go run cli/main/main.go twitter x0rzkov

And I have the following error displayed:

twitter_inserter_users_1     | (/app/db/utils.go:18)
twitter_inserter_users_1     | [2020-05-09 05:02:20]  pq: null value in column "username" violates not-null constraint
twitter_inserter_users_1     |
twitter_inserter_users_1     | (/app/db/utils.go:18)
twitter_inserter_users_1     | [2020-05-09 05:02:20]  pq: null value in column "username" violates not-null constraint
twitter_inserter_users_1     |
twitter_inserter_users_1     | (/app/db/utils.go:18)
twitter_inserter_users_1     | [2020-05-09 05:02:20]  pq: null value in column "username" violates not-null constraint
twitter_inserter_users_1     |
twitter_inserter_users_1     | (/app/db/utils.go:18)
twitter_inserter_users_1     | [2020-05-09 05:02:20]  pq: null value in column "username" violates not-null constraint
twitter_inserter_users_1     | 2020/05/09 05:02:20 encountered error while working:  pq: null value in column "username" violates not-null constraint
twitter_inserter_users_1     | 2020/05/09 05:02:20 twitter_inserter_users is done here
twitter_inserter_users_1     | 2020/05/09 05:02:20 stopping twitter_inserter_users
twitter_inserter_users_1     | 2020/05/09 05:02:20 waiting for work to stop
twitter_inserter_users_1     | 2020/05/09 05:02:20 calling shutdown hooks
twitter_inserter_users_1     | 2020/05/09 05:02:20 shutting down qReader
my-kafka_1                   | [2020-05-09 05:02:27,069] INFO [GroupCoordinator 1001]: Preparing to restabilize group twitter.inserter.users with old generation 1 (kafka.coordinator.GroupCoordinator)
my-kafka_1                   | [2020-05-09 05:02:27,070] INFO [GroupCoordinator 1001]: Group twitter.inserter.users with generation 2 is now empty (kafka.coordinator.GroupCoordinator)
twitter_inserter_users_1     | 2020/05/09 05:02:27 shutting down postgres_client
twitter_inserter_users_1     | 2020/05/09 05:02:27 twitter_inserter_users is shut down
smag-mvp_twitter_inserter_users_1 exited with code 0

Is there any reason why it happens ?
Is it possible to fix it ?

Cheers,
X