title: How to setup circular reference in maven modules?
body: <p>I have this problem with building a maven project...</p>
  
  <p>A mvn project parent is set like this:</p>
  
  <pre><code>&lt;groupId&gt;com.company.system.ping&lt;/groupId&gt;
  &lt;artifactId&gt;system-ping&lt;/artifactId&gt;
  &lt;name&gt;system-ping&lt;/name&gt;    
  &lt;parent&gt;
      &lt;artifactId&gt;parent_lvl_1&lt;/artifactId&gt;
      &lt;groupId&gt;com.company.system&lt;/groupId&gt;
      &lt;version&gt;1.0-SNAPSHOT&lt;/version&gt;
  &lt;/parent&gt;
  </code></pre>
  
  <p>Then I look for said parent's POM and find this:</p>
  
  <pre><code>&lt;groupId&gt;com.company.system&lt;/groupId&gt;
  &lt;artifactId&gt;parent_lvl_1&lt;/artifactId&gt;
  &lt;packaging&gt;pom&lt;/packaging&gt;
  &lt;name&gt;_proj_test&lt;/name&gt;
  &lt;version&gt;1.0-SNAPSHOT&lt;/version&gt;
  &lt;parent&gt;
      &lt;artifactId&gt;parent_lvl_0&lt;/artifactId&gt;
      &lt;groupId&gt;com.company&lt;/groupId&gt;
      &lt;version&gt;1&lt;/version&gt;
  &lt;/parent&gt;
  </code></pre>
  
  <p>I finally look at the first parent and see this:</p>
  
  <pre><code>&lt;groupId&gt;com.company&lt;/groupId&gt;
  &lt;artifactId&gt;parent_lvl_0&lt;/artifactId&gt;
  &lt;packaging&gt;pom&lt;/packaging&gt;
  &lt;name&gt;_main&lt;/name&gt;
  &lt;version&gt;1&lt;/version&gt;
  &lt;description&gt;The whole Projects&lt;/description&gt;
  </code></pre>
  
  <p>Now I check the modules:</p>
  
  <pre><code>&lt;modules&gt;
      &lt;module&gt;../_proj_test&lt;/module&gt;
  
      ...
  
  &lt;/modules&gt;
  </code></pre>
  
  <p>The first parent module is referencing a child! So when I try</p>
  
  <blockquote>
    <p>mvn install</p>
  </blockquote>
  
  <p>on '_main' I get this:</p>
  
  <pre><code>[ERROR]   The project com.company.system:_proj_test:1.0-SNAPSHOT (C:\...\pom.xml) has 1 error
  [ERROR]     Non-resolvable parent POM: The repository system is offline but the artifact com.company:_main:pom:1 is not available in the local repository. and 'parent.relativePath' points at wrong local POM @ line 4, column 10 -&gt; [Help 2]
  [ERROR]
  </code></pre>
  
  <p>I translate this to: <strong><em>you parent requieres a module which requires you back</em></strong>. If I comment out everything in <strong><em>modules</em></strong> I can install everything correctly but this is NOT OK for me! How can I build the parent without building the module dependencies?</p>
  
  <p>Thank you!</p>