m2e lifecycle-mapping not found

Question

I am trying to use the solution described here to solve the annoying \"Plugin execution not covered by lifecycle configuration: org.codehaus.mojo:build-helper-maven-plugin:1

Answer 1

Maven is trying to download m2e's lifecycle-mapping artifact, which M2E uses to determine how to process plugins within Eclipse (adding source folders, etc.). For some reason this artifact cannot be downloaded. Do you have an internet connection? Can other artifacts be downloaded from repositories? Proxy settings?

For more details from Maven, try turning M2E debug output on (Settings/Maven/Debug Output checkbox) and it might give you more details as to why it cannot download from the repository.

Answer 2

It happens due to a missing plugin configuration (as per vaadin's demo pom.xml comment):

This plugin's configuration is used to store Eclipse m2e settings only. It has no influence on the Maven build itself.

<pluginManagement>
    <plugins>
        <!--This plugin's configuration is used to store Eclipse m2e ettings only. It has no influence on the Maven build itself.-->
        <plugin>
            <groupId>org.eclipse.m2e</groupId>
            <artifactId>lifecycle-mapping</artifactId>
            <version>1.0.0</version>
            <configuration>
                <lifecycleMappingMetadata>
                    <pluginExecutions>
                        <pluginExecution>
                            <pluginExecutionFilter>
                                <groupId>com.vaadin</groupId>
                                <artifactId>
                                    vaadin-maven-plugin
                                </artifactId>
                                <versionRange>
                                    [7.1.5,)
                                </versionRange>
                                <goals>
                                    <goal>resources</goal>
                                    <goal>update-widgetset</goal>
                                    <goal>compile</goal>
                                    <goal>update-theme</goal>
                                    <goal>compile-theme</goal>
                                </goals>
                            </pluginExecutionFilter>
                            <action>
                                <ignore></ignore>
                            </action>
                        </pluginExecution>
                    </pluginExecutions>
                </lifecycleMappingMetadata>
            </configuration>
        </plugin>
    </plugins>
</pluginManagement>

Answer 3

m2e 1.7 introduces a new syntax for lifecycle mapping metadata that doesn't cause this warning anymore:

<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>build-helper-maven-plugin</artifactId>
<executions>
    <execution>

        <!-- This executes the goal in Eclipse on project import.
             Other options like are available, eg ignore.  -->
        <?m2e execute?>

        <phase>generate-sources</phase>
        <goals><goal>add-source</goal></goals>
        <configuration>
            <sources>
                <source>src/bootstrap/java</source>
            </sources>
        </configuration>
    </execution>
</executions>
</plugin>

Answer 4

this step works on me : 1. Remove your project on eclipse 2. Re import project 3. Delete target folder on your project 4. mvn or mvnw install

Answer 5

I have opened a (trivial) bug for this at m2e. Vote for it if you want the warning message to be gone for good...

https://bugs.eclipse.org/bugs/show_bug.cgi?id=367870