Hi, We have several flink applications written with Flink 1.9.1 and Scala 2.11.12 and we are in the process of upgrading to Flink 1.11.2 and Scala 2.12.12. We are using maven to manage our application dependencies.
After updating the pom.xml file to use the upgraded versions of Scala and Flink as mentioned above, all the unit tests written with Scalatest 3.0.5(We are using flatspec style) fail with the following exception. org.apache.flink.shaded.guava18.com.google.common.util.concurrent.ExecutionError: java.lang.NoClassDefFoundError: scala/math/Ordering$$anon$9 at org.apache.flink.shaded.guava18.com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2201) at org.apache.flink.shaded.guava18.com.google.common.cache.LocalCache.get(LocalCache.java:3937) at org.apache.flink.shaded.guava18.com.google.common.cache.LocalCache$LocalManualCache.get(LocalCache.java:4739) at org.apache.flink.api.scala.typeutils.TraversableSerializer$.compileCbf(TraversableSerializer.scala:184) at org.apache.flink.api.scala.typeutils.TraversableSerializer.compileCbf(TraversableSerializer.scala:51) at org.apache.flink.api.scala.typeutils.TraversableSerializer.<init>(TraversableSerializer.scala:41) Cause: java.lang.NoClassDefFoundError: scala/math/Ordering$$anon$9 at scala.tools.nsc.transform.LambdaLift$LambdaLifter.<init>(LambdaLift.scala:67) at scala.tools.nsc.transform.LambdaLift.newTransformer(LambdaLift.scala:49) at scala.tools.nsc.transform.Transform$Phase.apply(Transform.scala:30) at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:441) at scala.tools.nsc.Global$GlobalPhase.run(Global.scala:392) at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1467) at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1451) at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$ToolBoxGlobal.wrapInPackageAndCompile(ToolBoxFactory.scala:201) at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$ToolBoxGlobal.compile(ToolBoxFactory.scala:256) at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl.$anonfun$compile$13(ToolBoxFactory.scala:433) ... Cause: java.lang.ClassNotFoundException: scala.math.Ordering$$anon$9 at java.net.URLClassLoader.findClass(URLClassLoader.java:382) at java.lang.ClassLoader.loadClass(ClassLoader.java:418) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352) at java.lang.ClassLoader.loadClass(ClassLoader.java:351) at scala.tools.nsc.transform.LambdaLift$LambdaLifter.<init>(LambdaLift.scala:67) [flink-akka.actor.default-dispatcher-3] INFO org.apache.flink.runtime.taskexecutor.DefaultJobLeaderService - Stop job leader service. at scala.tools.nsc.transform.LambdaLift.newTransformer(LambdaLift.scala:49) [flink-akka.actor.default-dispatcher-3] INFO org.apache.flink.runtime.state.TaskExecutorLocalStateStoresManager - Shutting down TaskExecutorLocalStateStoresManager. at scala.tools.nsc.transform.Transform$Phase.apply(Transform.scala:30) at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:441) at scala.tools.nsc.Global$GlobalPhase.run(Global.scala:392) at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1467) The app itself compiles without issues and this can be verified by running mvn clean package `mvn clean package -DskipTests` In order to troubleshoot/narrow down the issue, I upgraded the flink package from 1.9.1 to to 1.11.2 while keeping the scala version the same i.e 2.11.12 instead of 2.12.12 and this seems to have resolved the issue. The app compiles and the test cases pass as well. Is this a known compatibility issue between Flink 1.11.2 and Scala 2.12.12? Thanks, Sourabh
