We recently upgraded a dev instance of Foreman (and associated proxies) to 1.8.0 and are running into an issue where re-importing an environment where class parameters have been removed does not actually remove those parameters in Foreman for that env.

The initial way we found this was that the ENC output for clients included the deprecated parameters (this was after the re-import), causing Puppet runs to fail ("no such class parameter"). Additionally, when we try to re-import, Foreman claims there are still changes in the environment that it doesn't know about.

As a workaround, we moved all hosts off that environment, deleted it, and re-imported it, and its signatures were then correct.

Unfortunately, I didn't check beforehand if any hosts still had those removed parameters set, I later thought that that might've been the issue. (I'm not sure if moving the hosts off that environment and deleting it would've removed that information).