When a Jetty 12 Jenkins test harness is used (i.e., one built from the prototype branch of jenkins-test-harness), tests based on these harnesses fail:

• src/test/java/org/jvnet/hudson/test/JenkinsRuleNonLocalhost.java
• src/test/java/org/jvnet/hudson/test/RestartableJenkinsNonLocalhostRule.java

Ideally a change could be found that can be delivered against the current release of Jetty 10 while also being forward compatible with Jetty 12. If not, then the PR will have to remain in draft until we release JTH with Jetty 12 support. Either way, we should prepare the PR in advance.