GMaven build fails with "An API incompatibility was encountered"

Question

While trying to compile my project using the Maven Gmaven plugin, the following error occurred:

[ERROR] Failed to execute goal org.codehaus.gmaven:gmaven-plugin:1.4:compile (default) on project concorde-web: Execution default of goal org.codehaus.gmaven:gmaven-plugin:1.4:compile failed: An API incompatibility was encountered while executing org.codehaus.gmaven:gmaven-plugin:1.4:compile: java.lang.NoSuchMethodError: org.codehaus.groovy.ast.ModuleNode.getStarImports()Ljava/util/List;

Googling suggests that this is because of multiple groovy versions ending up in my dependency chain. However, after checking the full dependency tree, I find that there is only one dependency in the full tree.

Here's the excerpt of my pom.xml:

    <!-- Groovy dependencies -->
    <dependency>
        <groupId>org.codehaus.groovy</groupId>
        <artifactId>groovy-all</artifactId>
        <version>1.8.5</version>
    </dependency>
    <!-- ... snip ... -->

        <plugin>
            <groupId>org.codehaus.gmaven</groupId>
            <artifactId>gmaven-plugin</artifactId>
            <version>1.4</version>
            <executions>
                <execution>
                    <goals>
                        <goal>generateStubs</goal>
                        <goal>compile</goal>
                        <goal>generateTestStubs</goal>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>

Answer 1

This is caused by a missing providerSelection element from the GMaven plugin definition.

The correct GMaven definition looks as follows:

        <plugin>
            <groupId>org.codehaus.gmaven</groupId>
            <artifactId>gmaven-plugin</artifactId>
            <version>1.4</version>
            <configuration>
                <providerSelection>1.8</providerSelection>
            </configuration>
            <executions>
                <execution>
                    <goals>
                        <goal>generateStubs</goal>
                        <goal>compile</goal>
                        <goal>generateTestStubs</goal>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>