<plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <executions>
          <execution>
            <id>test</id>
            <phase>package</phase>
            <goals>
              <goal>compile</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

        <artifactId>maven-it-plugin-expression</artifactId>
        <version>2.1-SNAPSHOT</version>
        <executions>
          <execution>
            <phase>validate</phase>
            <goals>
              <goal>eval</goal>
            </goals>
            <configuration>
              <outputFile>target/extension.properties</outputFile>
              <expressions>
                <expression>project/build/extensions</expression>

            if (projectBuilds.isEmpty()) {
                throw new NoGoalSpecifiedException("No goals have been specified for this build."
                        + " You must specify a valid lifecycle phase or a goal in the format <plugin-prefix>:<goal> or"
                        + " <plugin-group-id>:<plugin-artifact-id>[:<plugin-version>]:<goal>."

 */
public class DuplicateMojoDescriptorException extends InvalidPluginDescriptorException {

    public DuplicateMojoDescriptorException(
            String goalPrefix, String goal, String existingImplementation, String newImplementation) {
        super("Goal: " + goal + " already exists in the plugin descriptor for prefix: " + goalPrefix
                + System.lineSeparator() + "Existing implementation is: " + existingImplementation

              <pluginClassLoaderOutput>target/pcl.properties</pluginClassLoaderOutput>
            </configuration>
            <goals>
              <goal>load</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

        return Plugin.newBuilder()
                .groupId("org.apache.maven.plugins")
                .artifactId(artifactId)
                .executions(Arrays.stream(goals)
                        .map(goal -> PluginExecution.newBuilder()
                                .id("default-" + goal)
                                .goals(List.of(goal))
                                .build())

        return Plugin.newBuilder()
                .groupId("org.apache.maven.plugins")
                .artifactId(artifactId)
                .executions(Arrays.stream(goals)
                        .map(goal -> PluginExecution.newBuilder()
                                .id("default-" + goal)
                                .goals(List.of(goal))
                                .build())

import org.codehaus.plexus.components.secdispatcher.SecDispatcher;

import static org.apache.maven.cling.invoker.mvnenc.EncryptInvoker.OK;

/**
 * The "diag" goal. It should always run, despite it overrides configured goal support.
 */
@Singleton
@Named("diag")
public class Diag extends ConfiguredGoalSupport {
    @Inject
    public Diag(MessageBuilderFactory messageBuilderFactory, SecDispatcher secDispatcher) {

          </expressions>
        </configuration>
        <executions>
          <execution>
            <id>test</id>
            <phase>validate</phase>
            <goals>
              <goal>eval</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

        <groupId>org.apache.maven.its.plugins</groupId>
        <artifactId>maven-it-plugin</artifactId>
        <version>0.1</version>
        <executions>
          <execution>
            <goals>
              <goal>xpp3-reader</goal>
            </goals>
            <phase>generate-sources</phase>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>