which corrected itself after a restart. The 1.83 plugin was in use (at least after the restart—not sure about before); the inner class seems to be this:
Environment is not meant to be serializable AFAICT so I am not sure why this was producing a serialization-related error message. But if this class does in fact get sent over the wire, using an anonymous inner class is dangerous. Refactor into a named static member class instead. Or perhaps some other inner class was supposed to be serializable, and got confused with this one due to the generic name $2, in which case there would be a similar fix.
The job was a Maven moduleset, with no configuration from the plugin.
By the way various copies of
could be factored into a single constant; or better yet, use the factory method in Environment with an empty EnvVars.