java-specialagent: Jetty ClassNotFoundException on Jetty 9.2.10.v20150310

I am running a custom build of specialagent. I tried using the rule ‘specialagent-web-servlet-filter’, by setting the Jetty version to the one I needed, but keeping everything else unchanged. When I do so, I seem to get some strange classloading issues.

One that I can’t overcome yet is this ClassNotFoundException:

2019-08-07 14:18:51,95947 java.lang.NoClassDefFoundError: org/eclipse/jetty/http/HttpMethod
2019-08-07 14:18:51,95950       at org.eclipse.jetty.servlets.GzipFilter.init(GzipFilter.java:200)
2019-08-07 14:18:51,95950       at org.eclipse.jetty.servlets.IncludableGzipFilter.init(IncludableGzipFilter.java:59)
2019-08-07 14:18:51,95950       at org.eclipse.jetty.servlet.FilterHolder.initialize(FilterHolder.java:138)
2019-08-07 14:18:51,95951       at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:852)
2019-08-07 14:18:51,95951       at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:298)
2019-08-07 14:18:51,95952       at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1349)
2019-08-07 14:18:51,95952       at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1342)
2019-08-07 14:18:51,95953       at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:741)
2019-08-07 14:18:51,95955       at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:505)
2019-08-07 14:18:51,95956       at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
2019-08-07 14:18:51,95956       at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
2019-08-07 14:18:51,95957       at org.eclipse.jetty.server.Server.start(Server.java:387)
2019-08-07 14:18:51,95957       at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
2019-08-07 14:18:51,95957       at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
2019-08-07 14:18:51,95958       at org.eclipse.jetty.server.Server.doStart(Server.java:354)
2019-08-07 14:18:51,95959       at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
2019-08-07 14:18:51,95960       at com.example.eslauncher.CoreServerInstance.startAndJoinThread(CoreServerInstance.java:139)
2019-08-07 14:18:51,95960       at com.example.eslauncher.JettyServer.main(JettyServer.java:87)
2019-08-07 14:18:51,95960 Caused by: java.lang.ClassNotFoundException: org.eclipse.jetty.http.HttpMethod
2019-08-07 14:18:51,95961       at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
2019-08-07 14:18:51,95962       at org.eclipse.jetty.webapp.WebAppClassLoader.findClass(WebAppClassLoader.java:510)
2019-08-07 14:18:51,95962       at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:441)
2019-08-07 14:18:51,95962       at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:403)
2019-08-07 14:18:51,95963       ... 18 common frames omitted

Any ideas of what is causing this? I realize that it is likely a Jetty version mismatch, since these rules targeted a later version, but any ideas would be helpful of where to start.