i vaguely remember years ago, somebody told me that, whatever name they were using for the

r10k

wrapper now known as "code manager", had some kind of secret API that it used to (1) wait until the compiler wasn't using a given environment, (2) "lock" that environment so the compiler wouldn't use it, (3) rebuild the files in the environment, and (4) "unlock" it so the compiler could build catalogs again ... but they also said "i think that's an internal thing that puppetlabs (at the time) doesn't want to share the details of"