title: m2e lifecycle-mapping not found
body: <p>I am trying to use the solution <a href="https://www.eclipse.org/m2e/documentation/m2e-execution-not-covered.html" rel="noreferrer">described here</a> to solve the annoying "Plugin execution not covered by lifecycle configuration: org.codehaus.mojo:build-helper-maven-plugin:1.7:add-source (execution: default, phase: generate-sources)" when I place the following plugin on my pom.xml:</p>
  
  <pre><code>&lt;plugin&gt;
  &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
  &lt;artifactId&gt;build-helper-maven-plugin&lt;/artifactId&gt;
  &lt;executions&gt;
      &lt;execution&gt;
          &lt;phase&gt;generate-sources&lt;/phase&gt;
          &lt;goals&gt;&lt;goal&gt;add-source&lt;/goal&gt;&lt;/goals&gt;
          &lt;configuration&gt;
              &lt;sources&gt;
                  &lt;source&gt;src/bootstrap/java&lt;/source&gt;
              &lt;/sources&gt;
          &lt;/configuration&gt;
      &lt;/execution&gt;
  &lt;/executions&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>But when I run mvn clean install I get this:</p>
  
  <p>Reason: POM 'org.eclipse.m2e:lifecycle-mapping' not found in repository: Unable to download the artifact from any repository</p>
  
  <p>Does anyone have a clue on how to make m2e and maven happy?</p>