Why am I receiving a "Plugin execution not covered by lifecycle configuration with GWT" error?

Question

I'm using STS and I imported a GWT project from another machine. The project uses m2eclipse. I'm getting these two errors when building the project:

Plugin execution not covered by lifecycle configuration: org.codehaus.mojo:gwt-maven-plugin:2.2.0:i18n (execution: default, phase: generate-sources)    pom.xml /contactsgwt    line 175
Plugin execution not covered by lifecycle configuration: org.apache.maven.plugins:maven-war-plugin:2.1.1:exploded (execution: default, phase: compile)  pom.xml /contactsgwt    line 198

What's wrong? Is there any further configuration that needs to be done so the gwt maven plugin works?

The pom.xml code causing the error:

<!-- GWT Maven Plugin -->
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>gwt-maven-plugin</artifactId>
    <version>2.2.0</version>
    <executions>
        <execution>
            <goals>
                <goal>compile</goal>
                <goal>test</goal>
                <goal>i18n</goal>
            </goals>
        </execution>
    </executions>
    <!-- Plugin configuration. There are many available options, see gwt-maven-plugin documentation at codehaus.org -->
    <configuration>
        <runTarget>Contacts.html</runTarget>
        <hostedWebapp>${webappDirectory}</hostedWebapp
        <i18nMessagesBundle>es.indra.gwt.contactsgwt.client.ContactsMessages</i18nMessagesBundle>
    </configuration>
</plugin>

<!-- Copy static web files before executing gwt:run -->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.1.1</version>
    <executions>
        <execution>
            <phase>compile</phase>
            <goals>
                <goal>exploded</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <webappDirectory>${webappDirectory}</webappDirectory>
    </configuration>
</plugin>

<plugin>
    <groupId>org.maven.ide.eclipse</groupId>
    <artifactId>lifecycle-mapping</artifactId>
    <version>0.9.9-SNAPSHOT</version>
    <configuration>
        <mappingId>generic</mappingId>
        <configurators></configurators>
        <mojoExecutions>
            <mojoExecution runOnIncremental="true">org.codehaus.mojo:gwt-maven-plugin:2.2.0:i18n</mojoExecution>
            <mojoExecution runOnIncremental="true">org.apache.maven.plugins:maven-resources-plugin:2.4.1:resources</mojoExecution>
            <mojoExecution runOnIncremental="false">org.apache.maven.plugins:maven-compiler-plugin:2.0.2:compile</mojoExecution>
            <mojoExecution runOnIncremental="false">org.apache.maven.plugins:maven-war-plugin:2.1.1:exploded</mojoExecution>
            <mojoExecution runOnIncremental="false">org.apache.maven.plugins:maven-resources-plugin:2.4.1:testResources</mojoExecution>
        </mojoExecutions>
    </configuration>
</plugin>

Solution

If you use Eclipse Indigo (3.7) you have to activate the lifecycle plugin. See here for more details.

Just add this pluginManagement section to your build section of your pom.xml file

<pluginManagement>
    <plugins>
        <plugin>
            <groupId>org.eclipse.m2e</groupId>
            <artifactId>lifecycle-mapping</artifactId>
            <version>1.0.0</version>
            <configuration>
                <lifecycleMappingMetadata>
                    <pluginExecutions>
                        <pluginExecution>
                            <pluginExecutionFilter>
                                <groupId>org.codehaus.mojo</groupId>
                                <artifactId>gwt-maven-plugin</artifactId>
                                <versionRange>[2.4.0,)</versionRange>
                                <goals>
                                    <goal>resources</goal>
                                    <goal>compile</goal>
                                    <goal>i18n</goal>
                                    <goal>generateAsync</goal>
                                </goals>
                            </pluginExecutionFilter>
                            <action>
                                <execute />
                            </action>
                        </pluginExecution>
                        <pluginExecution>
                            <pluginExecutionFilter>
                                <groupId>org.apache.maven.plugins</groupId>
                                <artifactId>maven-war-plugin</artifactId>
                                <versionRange>[2.1.1,)</versionRange>
                                <goals>
                                    <goal>exploded</goal>
                                </goals>
                            </pluginExecutionFilter>
                            <action>
                                <execute />
                            </action>
                        </pluginExecution>
                    </pluginExecutions>
                </lifecycleMappingMetadata>
            </configuration>
        </plugin>
    </plugins>
</pluginManagement>