mixed compile with scala

pom.xml

    <dependencies>
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>${scala.version}</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.2.0</version>
                <configuration>
                    <recompileMode>incremental</recompileMode>
                    <args>
                        <arg>-target:jvm-${java.version}</arg>
                    </args>
                    <javacArgs>
                        <javacArg>-source</javacArg>
                        <javacArg>${java.version}</javacArg>
                        <javacArg>-target</javacArg>
                        <javacArg>${java.version}</javacArg>
                    </javacArgs>
                </configuration>
                <executions>
                    <execution>
                        <id>scala-compile-first</id>
                        <phase>process-resources</phase>
                        <goals>
                            <goal>add-source</goal>
                            <goal>compile</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>scala-test-compile</id>
                        <phase>process-test-resources</phase>
                        <goals>
                            <goal>testCompile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <executions>
                    <execution>
                        <id>default-compile</id>
                        <phase>none</phase>
                    </execution>
                    <execution>
                        <id>default-testCompile</id>
                        <phase>none</phase>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>