As was mentioned in yesterday’s pre-release announcement, we have been prepping and testing a chef client build versioned 12.8.1. We have just promoted that build and you should now find it on the public downloads site.
You can install using curl https://omnitruck.chef.io/install.sh | sudo bash -s -- on Linux or . { iwr -useb https://omnitruck.chef.io/install.ps1 } | iex; install on Windows and any other sources which use Omnitruck have the correct 12.8.1 package already.
For details on what features and bugs are included, see the change log and the release notes.
Matt