ActiveRecord::RecordNotUnique: Mysql2::Error: Duplicate entry '439679' for key 'mentor_testimonials.index_mentor_testimonials_on_discussion_id' (ActiveRecord::RecordNotUnique)

[ops-handler]

Error

Duplicate entry '439679' for key 'mentor_testimonials.index_mentor_testimonials_on_discussion_id' (Mysql2::Error)

Stack trace

mysql2/client.rb:151 in _query
mysql2/client.rb:151 in block in Mysql2::Client#query
mysql2/client.rb:150 in Thread.handle_interrupt
mysql2/client.rb:150 in query
active_record/connection_adapters/mysql2/database_statements.rb:100 in block (2 levels) in ActiveRecord::ConnectionAdapters::Mysql2::DatabaseStatements#raw_execute
active_record/connection_adapters/abstract_adapter.rb:1027 in block in ActiveRecord::ConnectionAdapters::AbstractAdapter#with_raw_connection
active_support/concurrency/null_lock.rb:9 in synchronize
active_record/connection_adapters/abstract_adapter.rb:999 in with_raw_connection
active_record/connection_adapters/mysql2/database_statements.rb:98 in block in ActiveRecord::ConnectionAdapters::Mysql2::DatabaseStatements#raw_execute
active_support/notifications/instrumenter.rb:58 in instrument

Tracking Details

• Project: exercism-rails
• Sentry: ActiveRecord::RecordNotUnique: Mysql2::Error: Duplicate entry '439679' for key 'mentor_testimonials.index_mentor_testimonials_on_discussion_id' (ActiveRecord::RecordNotUnique)
• Culprit: API::Solutions::MentorDiscussionsController#finish
• First seen: Apr 11, 2026