I recently upgraded my Jaba plugin to 4.1 ans since this my sonar-scanner is failing with NoClassDefFoundError exception regrading Google Gueva:
NFO: Scanner configuration file: /nfs/iil/disks/iec_sws2/tools/sonar-scanner-2.6.1/conf/sonar-scanner.properties
INFO: Project root configuration file: /tmp/jenkins/workspace/start-web/startweb/sonar-project.properties
INFO: SonarQube Scanner 2.6.1
INFO: Java 1.8.0_92 Oracle Corporation (64-bit)
INFO: Linux 3.0.101-0.7.29.1.9310.1.PTF-default amd64
INFO: User cache: /tmp/.sonar/cache
INFO: Load global repositories
INFO: Load global repositories (done) | time=257ms
INFO: User cache: /tmp/.sonar/cache
INFO: Load plugins index
INFO: Load plugins index (done) | time=8ms
INFO: SonarQube server 5.6
INFO: Default locale: "en_US", source code encoding: "UTF-8"
Exception in thread "main" java.lang.NoClassDefFoundError: com/google/common/collect/ImmutableList
at org.sonar.plugins.java.JavaPlugin.define(JavaPlugin.java:44)
at org.sonar.batch.bootstrap.ExtensionInstaller.install(ExtensionInstaller.java:55)
at org.sonar.batch.task.TaskContainer.addTaskExtensions(TaskContainer.java:62)
at org.sonar.batch.task.TaskContainer.doBeforeStart(TaskContainer.java:49)
at org.sonar.core.platform.ComponentContainer.startComponents(ComponentContainer.java:140)
at org.sonar.core.platform.ComponentContainer.execute(ComponentContainer.java:127)
at org.sonar.batch.bootstrap.GlobalContainer.executeTask(GlobalContainer.java:106)
at org.sonar.batch.bootstrapper.Batch.executeTask(Batch.java:119)
at org.sonarsource.scanner.api.internal.batch.BatchIsolatedLauncher.execute(BatchIsolatedLauncher.java:62)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.sonarsource.scanner.api.internal.IsolatedLauncherProxy.invoke(IsolatedLauncherProxy.java:60)
at com.sun.proxy.$Proxy0.execute(Unknown Source)
at org.sonarsource.scanner.api.EmbeddedScanner.doExecute(EmbeddedScanner.java:240)
at org.sonarsource.scanner.api.EmbeddedScanner.runAnalysis(EmbeddedScanner.java:151)
at org.sonarsource.scanner.cli.Main.runAnalysis(Main.java:110)
at org.sonarsource.scanner.cli.Main.execute(Main.java:72)
at org.sonarsource.scanner.cli.Main.main(Main.java:60)
Caused by: java.lang.ClassNotFoundException: com.google.common.collect.ImmutableList
at org.sonar.classloader.ParentFirstStrategy.loadClass(ParentFirstStrategy.java:39)
at org.sonar.classloader.ClassRealm.loadClass(ClassRealm.java:87)
at org.sonar.classloader.ClassRealm.loadClass(ClassRealm.java:76)
... 20 more