Symfony 5 - Semaphore extension (sysvsem) is required
i also had this problem, you can change the store for locking:https://symfony.com/doc/current/components/lock.html#available-stores
my solution was to change in .env.local
###> symfony/lock #### Choose one of the stores below# postgresql+advisory://db_user:db_password@localhost/db_nameLOCK_DSN=semaphore###< symfony/lock ###to :
###> symfony/lock #### Choose one of the stores below# postgresql+advisory://db_user:db_password@localhost/db_nameLOCK_DSN=flock###< symfony/lock ###