Thank you for the response but this error continues to happen with Scala 2.12.7. The app itself continues to compile without errors but the test cases fail with the same error.
Seems to be related to https://issues.apache.org/jira/browse/FLINK-12461 I have set the Scala version in pom.xml file and I have used this property value for all dependencies present. <properties> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <encoding>UTF-8</encoding> <scala.version>2.12.7</scala.version> <scala.compat.version>2.12</scala.compat.version> <aws.sdk.version>1.11.461</aws.sdk.version> <spec2.version>4.2.0</spec2.version> </properties> However, I ran into the same error 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) and it occurs if I use a Scala mutable/immutable map data-structure in my code. Sample test code: val data: scala.collection.mutable.Map[String, String] = scala.collection.mutable.Map("key1" -> "v1", "key2" -> "v2") val kafkaMsg: String = write( SampleCaseClass(14L, "23FC", 10L, data) ) val stream: DataStream[SampleCaseClass] = env.addSource(new MockKafkaSource(kafkaMsg)). flatMap(new SampleCaseClassMapper) I am including part of pom file related to test packages for reference. <dependency> <groupId>org.scalatest</groupId> <artifactId>scalatest_${scala.compat.version}</artifactId> <version>3.2.3</version> <scope>test</scope> </dependency> <build> <sourceDirectory>src/main/scala</sourceDirectory> <testSourceDirectory>src/test/scala</testSourceDirectory> <plugins> <plugin> <groupId>net.alchim31.maven</groupId> <artifactId>scala-maven-plugin</artifactId> <version>4.4.0</version> <executions> <execution> <goals> <goal>compile</goal> <goal>testCompile</goal> </goals> <configuration> <args> <arg>-dependencyfile</arg> <arg>${project.build.directory}/.scala_dependencies</arg> </args> </configuration> </execution> </executions> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <version>2.22.2</version> <configuration> <skipTests>true</skipTests> </configuration> </plugin> <plugin> <groupId>org.scalatest</groupId> <artifactId>scalatest-maven-plugin</artifactId> <version>2.0.2</version> <configuration> <reportsDirectory>${project.build.directory}/surefire-reports</reportsDirectory> <junitxml>.</junitxml> <filereports>TestSuiteReport.txt</filereports> </configuration> <executions> <execution> <id>test</id> <goals> <goal>test</goal> </goals> </execution> </executions> </plugin> </plugins> </build> -- Sent from: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/