Error: el nombre de usuario ya existe

¿Por qué ocurre constantemente este error en mi foro? ¿Es seguro ignorarlo?

Excepción de trabajo: PG::UniqueViolation: ERROR: el valor de clave duplicada viola la restricción única "index_users_on_username"
DETALLE: La clave (username)=(ghazal1) ya existe.

Se necesita mucho más contexto: ¿cuál es el backtrace y qué hay en el entorno?

rastreo de pila:



/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rack-mini-profiler-1.1.3/lib/patches/db/pg.rb:69:in `async_exec_params'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rack-mini-profiler-1.1.3/lib/patches/db/pg.rb:69:in `exec_params'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:672:in `block (2 levels) in exec_no_cache'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/dependencies/interlock.rb:48:in `block in permit_concurrent_loads'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/concurrency/share_lock.rb:187:in `yield_shares'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/dependencies/interlock.rb:47:in `permit_concurrent_loads'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:671:in `block in exec_no_cache'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/abstract_adapter.rb:718:in `block (2 levels) in log'
/usr/local/lib/ruby/2.6.0/monitor.rb:235:in `mon_synchronize'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/abstract_adapter.rb:717:in `block in log'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/notifications/instrumenter.rb:24:in `instrument'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/abstract_adapter.rb:708:in `log'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:670:in `exec_no_cache'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:651:in `execute_and_clear'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/postgresql/database_statements.rb:111:in `exec_delete'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:174:in `update'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/abstract/query_cache.rb:22:in `update'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/relation.rb:460:in `update_all'
/var/www/discourse/app/models/email_log.rb:25:in `block en <class:EmailLog>'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:429:in `instance_exec'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:429:in `block en make_lambda'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:239:in `block en halting_and_conditional'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:518:in `block en invoke_after'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:518:in `each'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:518:in `invoke_after'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:136:in `run_callbacks'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:827:in `_run_create_callbacks'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/callbacks.rb:332:in `_create_record'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/timestamp.rb:111:in `_create_record'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/persistence.rb:906:in `create_or_update'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/callbacks.rb:328:in `block en create_or_update'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:135:in `run_callbacks'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-6.0.1/lib/active_support/callbacks.rb:827:in `_run_save_callbacks'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/callbacks.rb:328:in `create_or_update'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/timestamp.rb:129:in `create_or_update'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/persistence.rb:503:in `save!'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/validations.rb:53:in `save!'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/transactions.rb:319:in `block en save!'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/transactions.rb:375:in `block en with_transaction_returning_status'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:281:in `block en transaction'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/abstract/transaction.rb:280:in `block en within_new_transaction'
/usr/local/lib/ruby/2.6.0/monitor.rb:235:in `mon_synchronize'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/abstract/transaction.rb:278:in `within_new_transaction'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:281:in `transaction'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/transactions.rb:212:in `transaction'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/transactions.rb:366:in `with_transaction_returning_status'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/transactions.rb:319:in `save!'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-6.0.1/lib/active_record/suppressor.rb:48:in `save!'
/var/www/discourse/lib/email/sender.rb:217:in `send'
/var/www/discourse/app/jobs/regular/user_email.rb:60:in `execute'
/var/www/discourse/app/jobs/regular/critical_user_email.rb:15:in `execute'
/var/www/discourse/app/jobs/base.rb:232:in `block (2 levels) en perform'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rails_multisite-2.0.7/lib/rails_multisite/connection_management.rb:63:in `with_connection'
/var/www/discourse/app/jobs/base.rb:221:in `block en perform'
/var/www/discourse/app/jobs/base.rb:217:in `each'
/var/www/discourse/app/jobs/base.rb:217:in `perform'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:192:in `execute_job'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:165:in `block (2 levels) en process'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/middleware/chain.rb:128:in `block en invoke'
/var/www/discourse/lib/sidekiq/pausable.rb:138:in `call'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/middleware/chain.rb:130:in `block en invoke'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/middleware/chain.rb:133:in `invoke'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:164:in `block en process'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:137:in `block (6 levels) en dispatch'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/job_retry.rb:109:in `local'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:136:in `block (5 levels) en dispatch'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq.rb:37:in `block en <module:Sidekiq>'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:132:in `block (4 levels) en dispatch'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:250:in `stats'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:127:in `block (3 levels) en dispatch'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/job_logger.rb:8:in `call'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:126:in `block (2 levels) en dispatch'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/job_retry.rb:74:in `global'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:125:in `block en dispatch'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/logging.rb:48:in `with_context'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/logging.rb:42:in `with_job_hash_context'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:124:in `dispatch'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:163:in `process'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:83:in `process_one'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/processor.rb:71:in `run'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/util.rb:16:in `watchdog'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/sidekiq-5.2.7/lib/sidekiq/util.rb:25:in `block en safe_thread'



entorno:

hostname	talk-app
process_id	1581
application_version	a3157f0e38a2e4bed8af08ec3c8b0456840a7baa
current_db	default
current_hostname	talk.zabanshenas.com
job	Jobs::CriticalUserEmail
problem_db	default
time	1:30 am
	
opts	
type	signup
user_id	212749
email_token	22b8a53383a192d9f55753c11b2ed1ef
current_site_id	default

No sé si está relacionado o no. Registro usuarios mediante la API. Obtengo el nombre de usuario del usuario y verifico si existe con la API; si es así, elijo lo que Discourse sugiere. Sin embargo, muchas veces lo que se sugiere es en realidad un nombre de usuario real de un usuario que de alguna manera está roto. Es decir, cuando intento ver su perfil, obtengo una página de error de no encontrado.

Por cierto, reporté estos usuarios rotos aquí: