Missing class JCTree$JCCompilationUnit inside Eclipse

[Verdoso]

Hi there,
I'm having a strange issue with latest releases. Everything seems to work fine outside Eclipse, but the maven container inside Eclipse now complains about

org.apache.maven.plugin.PluginContainerException: A required class was missing while executing org.projectlombok:lombok-maven-plugin:1.16.20.0:delombok: com/sun/tools/javac/tree/JCTree$JCCompilationUnit

I tried upgrading to the latest release and that does not solve it.

It's not critical, as I can still run maven, even inside Eclipse, and it works fine. It just looks weird having the project tagged as "broken" when there is nothing wrong with it.

[awhitford]

What version of Eclipse? What OS? What is the precise JDK being used by Eclipse?

[Verdoso]

Eclipse: Oxygen.2 Release (4.7.2) (Build id: 20171218-0600)
Maven plugin m2e: 1.8.2.20171007-0217
Maven: Embedded 3.3.9/1.8.2.20171007-0216
Windows 10
Java 8x64

It happens in both my computers with the same installation.

[lars-sh]

I had just the same problem with a similar configuration. In case someone is looking for a workaround: @jeacott1 posted one at projectlombok/lombok#925 (comment). The following extract just adds the delombokTest goal to fix both of them.

<pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.eclipse.m2e</groupId>
                    <artifactId>lifecycle-mapping</artifactId>
                    <version>1.0.0</version>
                    <configuration>
                        <lifecycleMappingMetadata>
                            <pluginExecutions>
                                <pluginExecution>
                                    <pluginExecutionFilter>
                                        <groupId>org.projectlombok</groupId>
                                        <artifactId>lombok-maven-plugin</artifactId>
                                        <versionRange>[1,)</versionRange>
                                        <goals>
                                            <goal>delombok</goal>
                                            <goal>delombokTest</goal>
                                        </goals>
                                    </pluginExecutionFilter>
                                    <action>
                                        <ignore />
                                    </action>
                                </pluginExecution>
                            </pluginExecutions>
                        </lifecycleMappingMetadata>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>