Scala Maven Compiler: NullPointerException - scala

Question

I have just moved a project from scala 2.11.11 to 2.12.6
My build now throws the following exception:
error: java.lang.NullPointerException [INFO] at
scala.tools.nsc.transform.patmat.MatchTranslation$MatchTranslator.translateMatch(MatchTranslation.scala:215)
My pom.xml is below. Any advice on how to troubleshoot would be appreciated. The internet does not have any discussion of this issue
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>ikoda</groupId>
<artifactId>scalaML</artifactId>
<version>1.0-SNAPSHOT</version>
<inceptionYear>2008</inceptionYear>
<properties>
<scala.version>2.12.6</scala.version>
</properties>
<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${scala.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.specs</groupId>
<artifactId>specs</artifactId>
<version>1.2.5</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.clapper</groupId>
<artifactId>grizzled-slf4j_2.12</artifactId>
<version>1.3.2</version>
</dependency>
<!---spark-->
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-sql_2.11 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.11</artifactId>
<version>2.2.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.11</artifactId>
<version>2.2.0</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.scala-lang/scala-reflect -->
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-reflect</artifactId>
<version>2.11.12</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>15.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-streaming_2.11 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-streaming_2.11</artifactId>
<version>2.2.0</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-mllib_2.11 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-mllib_2.11</artifactId>
<version>2.2.0</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-graphx_2.11 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-graphx_2.11</artifactId>
<version>2.2.0</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.typesafe/config -->
<dependency>
<groupId>com.typesafe</groupId>
<artifactId>config</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>org.json4s</groupId>
<artifactId>json4s-core_2.12</artifactId>
<version>3.6.0-M4</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.github.scopt/scopt -->
<dependency>
<groupId>com.github.scopt</groupId>
<artifactId>scopt_2.10</artifactId>
<version>3.2.0</version>
</dependency>
<dependency>
<groupId>ikoda</groupId>
<artifactId>ikoda-utils</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>ikoda</groupId>
<artifactId>ikodatext-textAnalysis</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>com.datastax.spark</groupId>
<artifactId>spark-cassandra-connector_2.11</artifactId>
<version>2.0.7</version>
</dependency>
<dependency>
<groupId>edu.stanford.nlp</groupId>
<artifactId>stanford-corenlp</artifactId>
<version>3.8.0</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>edu.stanford.nlp</groupId>
<artifactId>stanford-corenlp</artifactId>
<version>3.8.0</version>
<classifier>models</classifier>
<scope>test</scope>
</dependency>
<dependency>
<groupId>edu.stanford.nlp</groupId>
<artifactId>stanford-corenlp</artifactId>
<version>3.8.0</version>
<classifier>models-chinese</classifier>
<scope>test</scope>
</dependency>
<dependency>
<groupId>edu.stanford.nlp</groupId>
<artifactId>stanford-corenlp</artifactId>
<version>3.8.0</version>
<classifier>models-english</classifier>
<scope>test</scope>
</dependency>
<!-- http://mvnrepository.com/artifact/edu.stanford.nlp/stanford-parser -->
<dependency>
<groupId>edu.stanford.nlp</groupId>
<artifactId>stanford-parser</artifactId>
<version>3.8.0</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-math3 -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-math3</artifactId>
<version>3.6.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.github.pathikrit/better-files -->
<dependency>
<groupId>com.github.pathikrit</groupId>
<artifactId>better-files_2.11</artifactId>
<version>3.4.0</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>src/main/scala</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<!-- exclude log4j.properties -->
<excludes>
<exclude>**/log4j.properties</exclude>
</excludes>
</configuration>
</plugin>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.3.3</version>
<executions>
<execution>
<phase>compile</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>create-archive</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>