title: Is packaging type 'pom' needed when not using project aggregation (multimodule)?
body: <p>I want to inherit the dependencies of a (parent) <code>pom.xml</code> in a child project in Maven 2.2.1; i.e. use project inheritance. It seems it is necessary to change the default packaging type from <code>jar</code> to <code>pom</code> in this case.</p>
  
  <p>However, doesn't <a href="http://maven.apache.org/guides/introduction/introduction-to-the-pom.html#Project_Inheritance" rel="noreferrer">the Maven2 documentation</a> state that the packaging type <code>pom</code> is necessary for project aggregation, i.e. multimodule projects which use submodules, but not for project inheritance?</p>
  
  <pre><code>&lt;project&gt;
   &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
   &lt;groupId&gt;example&lt;/groupId&gt;
   &lt;artifactId&gt;example-parent&lt;/artifactId&gt;
   &lt;version&gt;1&lt;/version&gt;
  
   &lt;dependencies&gt;
     &lt;dependency&gt;
       &lt;groupId&gt;log4j&lt;/groupId&gt;
       &lt;artifactId&gt;log4j&lt;/artifactId&gt;
       &lt;version&gt;1.2.14&lt;/version&gt;
     &lt;/dependency&gt;
   &lt;/dependencies&gt;
  &lt;/project&gt;
  
  &lt;project&gt;     
   &lt;parent&gt;
     &lt;groupId&gt;example&lt;/groupId&gt;
     &lt;artifactId&gt;example-parent&lt;/artifactId&gt;
     &lt;version&gt;1&lt;/version&gt;
   &lt;/parent&gt;
  
   &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
   &lt;groupId&gt;example&lt;/groupId&gt; 
   &lt;artifactId&gt;example-child&lt;/artifactId&gt;
  &lt;/project&gt;
  </code></pre>
  
  <p>But if you call Maven (e.g. <code>mvn clean</code>) with the above configuration, you get an error:</p>
  
  <pre class="lang-none prettyprint-override"><code>Project ID: example:example-child
  
  Reason: Parent: example:example-parent:jar:1 
   of project: example:example-child has wrong packaging: jar.
  Must be 'pom'. for project example:example-child
  </code></pre>
  
  <p>On other other hand, with the following entry:</p>
  
  <pre><code>&lt;project&gt; 
   ... 
   &lt;packaging&gt;pom&lt;/packaging&gt;
   ... 
  &lt;/project&gt;
  </code></pre>
  
  <p>in the parent <code>pom.xml</code>, Maven can be executed without any error.</p>
  
  <p>Is this behavior of Maven correct?</p>