Kotlin 1.5.0 in Maven Multi-Module: java.lang.UnsupportedClassVersionError

Question

I have a Multi-module Maven project. I had to import a maven module Vader (which uses a mix of Kotlin 1.5.0 and Java 11) and use it as a dependency for one of my modules which purely uses java 11. The code compiles well but at runtime I get this error: java.lang.UnsupportedClassVersionError: org/revcloud/vader/matchers/AnyMatchers has been compiled by a more recent version of the Java Runtime (class file version 59.0), this version of the Java Runtime only recognizes class file versions up to 55.0

The file for which I get this error is a .kt file in my dependency module. I don’t get this error for java files. On the dependency module (vader) I made sure jvmTarget is set to java 11 and jdkHome points to java 11. I even confirmed by running javap -verbose AnyMatchers.class | grep “major” which gives me major version: 55

I am clueless as to what am I missing, where is this 59.0 coming from? Even my system only has JDK 11 and JDK 15 is not installed.

PFB the <build> section of pom.xml for dependency project(vader). (This has lombok too. So I delombok first into target/delombok and kotlin-maven-plugin picks up sources from this place. However none of the lombok annotations are used in Kotlin classes)

<build>
    <sourceDirectory>${project.build.directory}/delombok</sourceDirectory>
    <testSourceDirectory>${project.build.directory}/delombok-test</testSourceDirectory>
    <plugins>
        <plugin>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-maven-plugin</artifactId>
            <version>${kotlin.version}</version>
            <configuration>
                <jvmTarget>${kotlin.compiler.jvmTarget}</jvmTarget>
                <jdkHome>${kotlin.compiler.jdkHome}</jdkHome>
            </configuration>
            <executions>
                <execution>
                    <id>compile</id>
                    <goals>
                        <goal>compile</goal>
                    </goals>
                    <configuration>
                        <sourceDirs>
                            <sourceDir>${project.build.directory}/delombok</sourceDir>
                        </sourceDirs>
                    </configuration>
                </execution>
                <execution>
                    <id>test-compile</id>
                    <goals>
                        <goal>test-compile</goal>
                    </goals>
                    <configuration>
                        <sourceDirs>
                            <sourceDir>${project.build.directory}/delombok-test</sourceDir>
                        </sourceDirs>
                    </configuration>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok-maven-plugin</artifactId>
            <version>${lombok.version}.0</version>
            <configuration>
                <encoding>UTF-8</encoding>
            </configuration>
            <executions>
                <execution>
                    <id>delombok</id>
                    <phase>generate-sources</phase>
                    <goals>
                        <goal>delombok</goal>
                    </goals>
                    <configuration>
                        <sourceDirectory>src/main/java</sourceDirectory>
                        <outputDirectory>${project.build.directory}/delombok</outputDirectory>
                        <addOutputDirectory>false</addOutputDirectory>
                    </configuration>
                </execution>
                <execution>
                    <id>delombok-test</id>
                    <phase>generate-test-sources</phase>
                    <goals>
                        <goal>delombok</goal>
                    </goals>
                    <configuration>
                        <sourceDirectory>src/test/java</sourceDirectory>
                        <outputDirectory>${project.build.directory}/delombok-test</outputDirectory>
                        <addOutputDirectory>false</addOutputDirectory>
                    </configuration>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.8.1</version>
            <configuration>
                <source>${kotlin.compiler.jvmTarget}</source>
                <target>${kotlin.compiler.jvmTarget}</target>
            </configuration>
            <executions>
                <!-- Replacing default-compile as it is treated specially by maven -->
                <execution>
                    <id>default-compile</id>
                    <phase>none</phase>
                </execution>
                <!-- Replacing default-testCompile as it is treated specially by maven -->
                <execution>
                    <id>default-testCompile</id>
                    <phase>none</phase>
                </execution>
                <execution>
                    <id>java-compile</id>
                    <phase>compile</phase>
                    <goals>
                        <goal>compile</goal>
                    </goals>
                </execution>
                <execution>
                    <id>java-test-compile</id>
                    <phase>test-compile</phase>
                    <goals>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>3.2.0</version>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>3.0.0-M5</version>
        </plugin>
    </plugins>
</build>

Answer 1

Figured it out, had to change the Target JVM version for the Kotlin Compiler in Intellij