On Friday, December 17 a deadlock was introduced into a Dovecot package update that utilizes ApisCP's Bootstrapper build system to template configuration upon install. Systems affected began reporting spurious login rejections with first reports occurring shortly after 1 AM EST (-0500 GMT) during routine platform updates. The issue largely affected CentOS 8/Alma/Rocky Linux machines. CentOS 7 was unaffected in most timezones.
This is a companion discussion topic for the original entry at https://hq.apiscp.com/dovecot-upcp-multiple-deadlocks/