title: Why does maven ignore the add-source-goal?
body: <p>This is the build-section of my pom.xml. I have only one pom.xml for the whole project.</p>
  
  <pre><code>&lt;build&gt;
      &lt;pluginManagement&gt;
          &lt;plugins&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.eclipse.m2e&lt;/groupId&gt;
                  &lt;artifactId&gt;lifecycle-mapping&lt;/artifactId&gt;
                  &lt;version&gt;1.0.0&lt;/version&gt;
                  &lt;configuration&gt;
                      &lt;lifecycleMappingMetadata&gt;
                          &lt;pluginExecutions&gt;
                              &lt;pluginExecution&gt;
                                  &lt;pluginExecutionFilter&gt;
                                      &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
                                      &lt;artifactId&gt;build-helper-maven-plugin&lt;/artifactId&gt;
                                      &lt;versionRange&gt;[1.1,)&lt;/versionRange&gt;
                                      &lt;goals&gt;
                                          &lt;goal&gt;add-source&lt;/goal&gt;
                                      &lt;/goals&gt;
                                  &lt;/pluginExecutionFilter&gt;
                                  &lt;action&gt;
                                      &lt;execute /&gt;
                                  &lt;/action&gt;
                              &lt;/pluginExecution&gt;
                          &lt;/pluginExecutions&gt;
                      &lt;/lifecycleMappingMetadata&gt;
                  &lt;/configuration&gt;
              &lt;/plugin&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
                  &lt;artifactId&gt;build-helper-maven-plugin&lt;/artifactId&gt;
                  &lt;version&gt;1.1&lt;/version&gt;
                  &lt;executions&gt;
                      &lt;execution&gt;
                          &lt;id&gt;add-source&lt;/id&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/projects&lt;/source&gt;
                              &lt;/sources&gt;
                          &lt;/configuration&gt;
                      &lt;/execution&gt;
                  &lt;/executions&gt;
              &lt;/plugin&gt;
              &lt;plugin&gt;
                  &lt;artifactId&gt;maven-compiler-plugin&lt;/artifactId&gt;
                  &lt;version&gt;3.3&lt;/version&gt;
                  &lt;configuration&gt;
                      &lt;source&gt;1.8&lt;/source&gt;
                      &lt;target&gt;1.8&lt;/target&gt;
                  &lt;/configuration&gt;
                  &lt;dependencies&gt;
                  &lt;/dependencies&gt;
              &lt;/plugin&gt;
              &lt;plugin&gt;
                  &lt;artifactId&gt;maven-assembly-plugin&lt;/artifactId&gt;
                  &lt;version&gt;2.5.5&lt;/version&gt;
                  &lt;configuration&gt;
                      &lt;descriptors&gt;
                          &lt;descriptor&gt;src/main/assembly/jar-dep.xml&lt;/descriptor&gt;
                          &lt;descriptor&gt;src/main/assembly/src-zip.xml&lt;/descriptor&gt;
                          &lt;descriptor&gt;src/main/assembly/bin-zip.xml&lt;/descriptor&gt;
                      &lt;/descriptors&gt;
                      &lt;archive&gt;
                          &lt;manifest&gt;
                              &lt;mainClass&gt;myProject.Main&lt;/mainClass&gt;
                          &lt;/manifest&gt;
                      &lt;/archive&gt;
                      &lt;appendAssemblyId&gt;true&lt;/appendAssemblyId&gt;
                      &lt;archiverConfig&gt;
                          &lt;compress&gt;true&lt;/compress&gt;
                      &lt;/archiverConfig&gt;
                  &lt;/configuration&gt;
              &lt;/plugin&gt;
          &lt;/plugins&gt;
      &lt;/pluginManagement&gt;
  &lt;/build&gt;
  </code></pre>
  
  <p>If I remove the -tags, it comiles just fine, but eclipse complains as follows: Plugin execution not covered by lifecycle configuration: org.codehaus.mojo:build-helper-maven-plugin:1.1:add-source (execution: add-source, phase: generate-sources)</p>
  
  <p>If I leave the tags, eclipse shows no errors in the pom.xml, but the additional sources are not compiled and not added to the jar-files. What is wrong?</p>