Discourse Docker の再ビルドが「Unknown Migration Version」で失敗しました

./launcher rebuild myapp で再構築を試みたところ、以下のエラーが発生しました:

I, [2019-11-22T04:39:11.739534 #1]  INFO -- : > cd /var/www/discourse && su discourse -c 'bundle exec rake db:migrate'
rake aborted!
ArgumentError: Unknown migration version "6.0"; expected one of "4.2", "5.0", "5.1", "5.2"
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration/compatibility.rb:11:in `find'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:536:in `[]'
/var/www/discourse/plugins/discourse-akismet/db/migrate/20191031193436_remove_old_akismet_states.rb:3:in `<top (required)>'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.3/lib/active_support/dependencies.rb:291:in `require'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.3/lib/active_support/dependencies.rb:291:in `block in require'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.3/lib/active_support/dependencies.rb:257:in `load_dependency'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.3/lib/active_support/dependencies.rb:291:in `require'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:986:in `load_migration'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:982:in `migration'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:977:in `disable_ddl_transaction'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1350:in `use_transaction?'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1297:in `rescue in execute_migration_in_transaction'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1285:in `execute_migration_in_transaction'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1263:in `block in migrate_without_lock'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1262:in `each'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1262:in `migrate_without_lock'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1210:in `block in migrate'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1363:in `with_advisory_lock'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1210:in `migrate'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1036:in `up'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/migration.rb:1011:in `migrate'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/tasks/database_tasks.rb:172:in `migrate'
/var/www/discourse/lib/migration/safe_migrate.rb:52:in `migrate'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.3/lib/active_record/railties/databases.rake:60:in `block (2 levels) in <top (required)>'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-12.3.2/exe/rake:27:in `<top (required)>'
/usr/local/bin/bundle:23:in `load'
/usr/local/bin/bundle:23:in `<main>'

現在のベースイメージ:discourse/base 2.0.20191013-2320

他に必要な情報があればお知らせください。
ありがとうございます!

どのリリースバージョンをお使いですか?安定版、ベータ版、それともテスト通過版ですか?

安定版

Discourse のウェブサイトにアクセスすると表示されます:discourse v2.3.6

@gerhard さんは 10 日前にこれを修正済みです。stable版で問題を引き起こした 6.0 のマイグレーションがありました。

以下を実行してください:

git pull
./launcher rebuild app

アプリ.yml を myapp.yml に名前変更している場合は ./launcher rebuild myapp を実行してください。

その後、再度お試しください。動作しない場合はご報告ください。

はい、何度か試しました。
動作しません。

Akismet プラグインのマイルストーンを修正しました。アプリを再構築してお試しください。