danielbeck it is, also a Maven issue (CC aheritier).
Just to clarify, the issues happens, because the master acts as an agent in master<=>Maven communications when the Maven build starts. Remoting since 3.7 tries to initialize a default JAR cache and not surprisingly fails when you run the master in a Tomcat container.
It is actually similar to JENKINS-45755, likely a leftover. I will need to verify it manually, but likely picking a default cache in Launcher was a bad idea.
It would be also great to update Maven plugin to use less ancient Remoting APIs
oleg_nenashev is this a remoting issue?