How can I build a project that requires multiple versions of Scala? - scala

Question

When I tried to build spark-ts package using Maven by executing
mvn package
"BUILD FAILURE" occurred with the following error.
[INFO] --- scala-maven-plugin:3.2.2:compile (scala-compile-first) # sparkts ---
[WARNING] Expected all dependencies to require Scala version: 2.11.4
[WARNING] com.cloudera.sparkts:sparkts:0.4.0-SNAPSHOT requires scala version: 2.11.4
[WARNING] com.cloudera.sparkts:sparkts:0.4.0-SNAPSHOT requires scala version: 2.11.4
[WARNING] org.scala-lang:scalap:2.11.4 requires scala version: 2.11.4
[WARNING] com.cloudera.sparkts:sparkts:0.4.0-SNAPSHOT requires scala version: 2.11.4
[WARNING] org.scala-lang:scala-compiler:2.11.4 requires scala version: 2.11.4
[WARNING] org.scala-lang:scala-reflect:2.11.4 requires scala version: 2.11.4
[WARNING] org.scala-lang.modules:scala-xml_2.11:1.0.2 requires scala version: 2.11.1
[WARNING] Multiple versions of scala libraries detected!
[INFO] .../spark-timeseries-master/src/main/java:-1: info: compiling
[INFO] .../spark-timeseries-master/src/main/scala:-1: info: compiling
[INFO] Compiling 29 source files to .../spark-timeseries-master/target/classes at 1597272142962
[ERROR] error: scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
[ERROR] error: scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
[ERROR] at scala.reflect.internal.MissingRequirementError$.signal(MissingRequirementError.scala:17)
[ERROR] at scala.reflect.internal.MissingRequirementError$.notFound(MissingRequirementError.scala:18)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:53)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:45)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:45)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:66)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getClassByName(Mirrors.scala:102)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getRequiredClass(Mirrors.scala:105)
[ERROR] at scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass$lzycompute(Definitions.scala:257)
[ERROR] at scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass(Definitions.scala:257)
[ERROR] at scala.reflect.internal.Definitions$DefinitionsClass.init(Definitions.scala:1387)
[ERROR] at scala.tools.nsc.Global$Run.<init>(Global.scala:1053)
[ERROR] at scala.tools.nsc.Driver.doCompile(Driver.scala:31)
[ERROR] at scala.tools.nsc.MainClass.doCompile(Main.scala:23)
[ERROR] at scala.tools.nsc.Driver.process(Driver.scala:51)
[ERROR] at scala.tools.nsc.Driver.main(Driver.scala:64)
[ERROR] at scala.tools.nsc.Main.main(Main.scala)
[ERROR] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[ERROR] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[ERROR] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[ERROR] at java.base/java.lang.reflect.Method.invoke(Method.java:564)
[ERROR] at scala_maven_executions.MainHelper.runMain(MainHelper.java:164)
[ERROR] at scala_maven_executions.MainWithArgsInFile.main(MainWithArgsInFile.java:26)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 7.656 s
[INFO] Finished at: 2020-08-12T15:42:24-07:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal net.alchim31.maven:scala-maven-plugin:3.2.2:compile (scala-compile-first) on project sparkts: wrap: org.apache.commons.exec.ExecuteException: Process exited with an error: 1 (Exit value: 1) -> [Help 1]
Error message
I think the issue comes from the fact that the scala compiler depends on scala-xml, which requires an older version of scala. Is there any way fix the issue with multiple versions of scala?
Pom file for spark-ts looks like the following. It includes the "dependencies" that I specified, which still did not fix the issue. (Source code is here.)
<build>
<plugins>
<plugin>
<groupId>org.sonatype.plugins</groupId>
<artifactId>nexus-staging-maven-plugin</artifactId>
<version>1.6.7</version>
<extensions>true</extensions>
<configuration>
<serverId>ossrh</serverId>
<nexusUrl>https://oss.sonatype.org/</nexusUrl>
<autoReleaseAfterClose>true</autoReleaseAfterClose>
</configuration>
</plugin>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.2.2</version>
<configuration>
<scalaVersion>${scala.complete.version}</scalaVersion>
<javacArgs>
<javacArg>-source</javacArg>
<javacArg>${java.version}</javacArg>
<javacArg>-target</javacArg>
<javacArg>${java.version}</javacArg>
</javacArgs>
</configuration>
<executions>
<execution>
<phase>compile</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
<execution>
<id>scala-compile-first</id>
<phase>process-resources</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
<execution>
<id>scala-test-compile-first</id>
<phase>process-test-resources</phase>
<goals>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
<!-- This is what I added to fix the code. But, it still did not work... -->
<dependencies>
<dependency>
<groupId>org.scala-lang.modules</groupId>
<artifactId>scala-xml_2.11</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>org.scala-lang.modules</groupId>
<artifactId>scala-parser-combinators_2.11</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>org.scala-lang.modules</groupId>
<artifactId>scala-swing_2.11</artifactId>
<version>2.0.3</version>
</dependency>
</dependencies>
</plugin>
Edit: The problem was resolved after changing Java 10 to Java 8.