title: Lagom/Play + sbt-assembly: "deduplicate: different file contents found in the following"
body: <p>I'm trying to bundle jars in Lagom (uses Play) at a microservice level using sbt-assembly. Transitive dependencies in Play are a known issue as listed on <a href="https://github.com/sbt/sbt-assembly#exclude-specific-transitive-deps" rel="nofollow noreferrer">sbt-assembly's GitHub README</a>. Per the instructions on the README, I embed the below code in my build.sbt</p>
  
  <pre><code>libraryDependencies ~= { _ map {
    case m if m.organization == "com.typesafe.play" =&gt;
      m.exclude("commons-logging", "commons-logging").
        exclude("com.typesafe.play", "sbt-link")
    case m =&gt; m
  }}
  </code></pre>
  
  <p>I still see error as below. Does the above code actually go in a build.sbt file? How can I resolve this?</p>
  
  <pre><code>[error] /Users/zsm559/.ivy2/cache/io.netty/netty-codec-http/jars/netty-codec-http-4.0.41.Final.jar:META-INF/io.netty.versions.properties
  [error] /Users/zsm559/.ivy2/cache/io.netty/netty-codec/jars/netty-codec-4.0.41.Final.jar:META-INF/io.netty.versions.properties
  [error] /Users/zsm559/.ivy2/cache/io.netty/netty-transport/jars/netty-transport-4.0.41.Final.jar:META-INF/io.netty.versions.properties
  [error] /Users/zsm559/.ivy2/cache/io.netty/netty-buffer/jars/netty-buffer-4.0.41.Final.jar:META-INF/io.netty.versions.properties
  [error] /Users/zsm559/.ivy2/cache/io.netty/netty-common/jars/netty-common-4.0.41.Final.jar:META-INF/io.netty.versions.properties
  [error] /Users/zsm559/.ivy2/cache/io.netty/netty-handler/jars/netty-handler-4.0.41.Final.jar:META-INF/io.netty.versions.properties
  [error] /Users/zsm559/.ivy2/cache/io.netty/netty-transport-native-epoll/jars/netty-transport-native-epoll-4.0.41.Final-linux-x86_64.jar:META-INF/io.netty.versions.properties
  [error] deduplicate: different file contents found in the following:
  [error] /Users/zsm559/.ivy2/cache/commons-logging/commons-logging/jars/commons-logging-1.1.3.jar:org/apache/commons/logging/Log.class
  [error] /Users/zsm559/.ivy2/cache/org.slf4j/jcl-over-slf4j/jars/jcl-over-slf4j-1.7.21.jar:org/apache/commons/logging/Log.class
  [error] deduplicate: different file contents found in the following:
  [error] /Users/zsm559/.ivy2/cache/commons-logging/commons-logging/jars/commons-logging-1.1.3.jar:org/apache/commons/logging/LogConfigurationException.class
  [error] /Users/zsm559/.ivy2/cache/org.slf4j/jcl-over-slf4j/jars/jcl-over-slf4j-1.7.21.jar:org/apache/commons/logging/LogConfigurationException.class
  [error] deduplicate: different file contents found in the following:
  [error] /Users/zsm559/.ivy2/cache/commons-logging/commons-logging/jars/commons-logging-1.1.3.jar:org/apache/commons/logging/LogFactory.class
  [error] /Users/zsm559/.ivy2/cache/org.slf4j/jcl-over-slf4j/jars/jcl-over-slf4j-1.7.21.jar:org/apache/commons/logging/LogFactory.class
  [error] deduplicate: different file contents found in the following:
  [error] /Users/zsm559/.ivy2/cache/commons-logging/commons-logging/jars/commons-logging-1.1.3.jar:org/apache/commons/logging/impl/NoOpLog.class
  [error] /Users/zsm559/.ivy2/cache/org.slf4j/jcl-over-slf4j/jars/jcl-over-slf4j-1.7.21.jar:org/apache/commons/logging/impl/NoOpLog.class
  [error] deduplicate: different file contents found in the following:
  [error] /Users/zsm559/.ivy2/cache/commons-logging/commons-logging/jars/commons-logging-1.1.3.jar:org/apache/commons/logging/impl/SimpleLog$1.class
  [error] /Users/zsm559/.ivy2/cache/org.slf4j/jcl-over-slf4j/jars/jcl-over-slf4j-1.7.21.jar:org/apache/commons/logging/impl/SimpleLog$1.class
  [error] deduplicate: different file contents found in the following:
  [error] /Users/zsm559/.ivy2/cache/commons-logging/commons-logging/jars/commons-logging-1.1.3.jar:org/apache/commons/logging/impl/SimpleLog.class
  [error] /Users/zsm559/.ivy2/cache/org.slf4j/jcl-over-slf4j/jars/jcl-over-slf4j-1.7.21.jar:org/apache/commons/logging/impl/SimpleLog.class
  [error] deduplicate: different file contents found in the following:
  [error] /Users/zsm559/.ivy2/cache/com.typesafe.play/play_2.11/jars/play_2.11-2.5.10.jar:play/reference-overrides.conf
  [error] /Users/zsm559/.ivy2/cache/com.lightbend.lagom/lagom-cluster-core_2.11/jars/lagom-cluster-core_2.11-1.3.3.jar:play/reference-overrides.conf
  [error] /Users/zsm559/.ivy2/cache/com.lightbend.lagom/lagom-persistence-cassandra-core_2.11/jars/lagom-persistence-cassandra-core_2.11-1.3.3.jar:play/reference-overrides.conf
  [error] deduplicate: different file contents found in the following:
  [error] /Users/zsm559/.ivy2/cache/com.lightbend.lagom/lagom-persistence-cassandra-core_2.11/jars/lagom-persistence-cassandra-core_2.11-1.3.3.jar:test-embedded-cassandra.yaml
  [error] /Users/zsm559/.ivy2/cache/com.typesafe.akka/akka-persistence-cassandra_2.11/bundles/akka-persistence-cassandra_2.11-0.26.jar:test-embedded-cassandra.yaml
  </code></pre>