title: Maven (Eclipse plugin and mvn) not including main class with pom.xml setup
body: <p>I've been trying to work this out for the last few hours and I've got nowhere. I've just installed the Maven for Eclipse plugin (M2E, I think) and also the maven too, mvn. I've created a very simple Hello World project and am trying to get the built jar to run on using:
  java -jar pimidi-0.0.1-SNAPSHOT.jar</p>
  
  <p>Regardless of what I try, I always get the same error:
  no main manifest attribute, in target/pimidi-0.0.1-SNAPSHOT.jar</p>
  
  <p>Here is my pom.xml:</p>
  
  <pre><code>&lt;project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
      &lt;groupId&gt;com.dan&lt;/groupId&gt;
      &lt;artifactId&gt;pimidi&lt;/artifactId&gt;
      &lt;version&gt;0.0.1-SNAPSHOT&lt;/version&gt;
      &lt;packaging&gt;jar&lt;/packaging&gt;
  
      &lt;name&gt;pimidi&lt;/name&gt;
      &lt;url&gt;http://maven.apache.org&lt;/url&gt;
  
      &lt;properties&gt;
          &lt;project.build.sourceEncoding&gt;UTF-8&lt;/project.build.sourceEncoding&gt;
      &lt;/properties&gt;
  
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;junit&lt;/groupId&gt;
              &lt;artifactId&gt;junit&lt;/artifactId&gt;
              &lt;version&gt;3.8.1&lt;/version&gt;
              &lt;scope&gt;test&lt;/scope&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  &lt;/project&gt;
  &lt;build&gt;
      &lt;plugins&gt;
          &lt;plugin&gt;
              &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
              &lt;artifactId&gt;maven-eclipse-plugin&lt;/artifactId&gt;
              &lt;configuration&gt;
                  &lt;wtpversion&gt;1.5&lt;/wtpversion&gt;
              &lt;/configuration&gt;
          &lt;/plugin&gt;
          &lt;plugin&gt;
              &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
              &lt;artifactId&gt;maven-compiler-plugin&lt;/artifactId&gt;
              &lt;configuration&gt;
                  &lt;source&gt;1.6&lt;/source&gt;
                  &lt;target&gt;1.6&lt;/target&gt;
              &lt;/configuration&gt;
          &lt;/plugin&gt;
          &lt;plugin&gt;
              &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
              &lt;artifactId&gt;maven-jar-plugin&lt;/artifactId&gt;
              &lt;version&gt;2.4&lt;/version&gt;
              &lt;configuration&gt;
                  &lt;archive&gt;
                      &lt;manifest&gt;
                          &lt;mainClass&gt;com.dan.pimidi.App&lt;/mainClass&gt;
                      &lt;/manifest&gt;
                  &lt;/archive&gt;
              &lt;/configuration&gt;
          &lt;/plugin&gt;
      &lt;/plugins&gt;
  &lt;/build&gt;
  </code></pre>
  
  <p>I've tried countless different options within the manifest nodes of the POM (classpath, manifest location), different plugins (assembly, compile, etc) to no avail. On looking at the effective POM in Eclipse, I can see that maven-jar-plugin is already included from a higher-level POM an any changes to the project POM are omitted. </p>
  
  <p>Does anyone have any ideas about how to get this working? Apologies if this question lacks detail - I have expired my mental power for this evening. Any assistance would be greatly appreciated!</p>