The PrioritySorter plugin that we use for the build farm relies on some global configuration to be set in order for the job-specific configuration to be considered valid.

It seems like the 5.0.0 release added support for Jenkins Configuration-as-Code which means that scripting this should be easier than it used to be. My memory now serves that we've had this "oh wait what?" each time we've set up a new build farm cluster.

In the main Jenkins configuration we need to set the following:

Then there is a separate global Job Priorities configuration that needs to be created as well: