Starting an agent (both via ssh and from the command line) on a FreeBSD-12/arm64 agent sends the slave in an infinite loop for over five minutes. If started over ssh, jenkins will try launching a second (and third and so on) copy of the agent to the same result.

For some reason it did connect once, but I can't reproduce the correct behaviour. I've tried deleting and recreating the host, no changes.

Attaching stdout, stderr, remoting log and two thread dumps taken a few minutes after startup.

It would seem that the slave is looping forever in hudson.remoting.ClassFilter$RegExpClassFilter.add - maybe the fact that it's running on an interpreter-mode JVM makes it super inefficient at parsing regexes? Either way, it's been running at 100% CPU for over 15 minutes now and Jenkins still doesn't see the connection as up