title: Maven build invalid POM
body: <p>I am using Spring Boot 1.5.8 as parent POM for my project. While building, it keeps on giving warnings for some POMs. They are not errors, but I am uncomfortable with warnings as they might cause a problem in future that is difficult to trace.</p>
  
  <p>Maven version: 3.5.0</p>
  
  <p>Here is part of POM:</p>
  
  <pre><code>  &lt;parent&gt;
      &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
      &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
      &lt;version&gt;1.5.8.RELEASE&lt;/version&gt;
    &lt;/parent&gt;
  </code></pre>
  
  <p>Entire POM can be found at: <a href="https://paste.ubuntu.com/25828364/" rel="nofollow noreferrer">https://paste.ubuntu.com/25828364/</a></p>
  
  <p>Here is command used to create effective POM:</p>
  
  <pre><code>mvn -X help:effective-pom
  </code></pre>
  
  <p>Relevant part of the log</p>
  
  <pre><code>[DEBUG] =======================================================================
  [INFO] 
  [INFO] --- maven-help-plugin:2.2:effective-pom (default-cli) @ Apeiron ---
  [DEBUG] Using mirror mavenrepo (http://artifactory.zendu.com/mavenrepo) for snapshots (http://snapshots.maven.codehaus.org/maven2).
  [WARNING] The POM for org.apache.maven:maven-plugin-api:jar:2.2.1 is invalid, transitive dependencies (if any) will not be available: 3 problems were encountered while building the effective model for org.apache.maven:maven-plugin-api:[unknown-version]
  [ERROR] Invalid packaging for parent POM org.apache.maven:maven-plugin-api:[unknown-version], must be "pom" but is "jar" @ 
  [ERROR] Invalid packaging for parent POM org.apache.maven:maven-plugin-api:[unknown-version], must be "pom" but is "jar" @ 
  [FATAL] The parents form a cycle: org.apache.maven:maven-plugin-api:2.2.1 -&gt; org.apache.maven:maven-plugin-api:2.2.1 @ 
  
  [WARNING] The POM for org.apache.maven:maven-project:jar:2.0.6 is invalid, transitive dependencies (if any) will not be available: 3 problems were encountered while building the effective model for org.apache.maven:maven-project:[unknown-version]
  [ERROR] Invalid packaging for parent POM org.apache.maven:maven-project:[unknown-version], must be "pom" but is "jar" @ 
  [ERROR] Invalid packaging for parent POM org.apache.maven:maven-project:[unknown-version], must be "pom" but is "jar" @ 
  [FATAL] The parents form a cycle: org.apache.maven:maven-project:2.0.6 -&gt; org.apache.maven:maven-project:2.0.6 @ 
  
  [WARNING] The POM for org.apache.maven:maven-model:jar:2.0.6 is invalid, transitive dependencies (if any) will not be available: 3 problems were encountered while building the effective model for org.apache.maven:maven-model:[unknown-version]
  [ERROR] Invalid packaging for parent POM org.apache.maven:maven-model:[unknown-version], must be "pom" but is "jar" @ 
  [ERROR] Invalid packaging for parent POM org.apache.maven:maven-model:[unknown-version], must be "pom" but is "jar" @ 
  [FATAL] The parents form a cycle: org.apache.maven:maven-model:2.0.6 -&gt; org.apache.maven:maven-model:2.0.6 @ 
  
  [WARNING] The POM for org.apache.maven:maven-artifact:jar:2.0.6 is invalid, transitive dependencies (if any) will not be available: 3 problems were encountered while building the effective model for org.apache.maven:maven-artifact:[unknown-version]
  [ERROR] Invalid packaging for parent POM org.apache.maven:maven-artifact:[unknown-version], must be "pom" but is "jar" @ 
  [ERROR] Invalid packaging for parent POM org.apache.maven:maven-artifact:[unknown-version], must be "pom" but is "jar" @ 
  [FATAL] The parents form a cycle: org.apache.maven:maven-artifact:2.0.6 -&gt; org.apache.maven:maven-artifact:2.0.6 @ 
  
  [DEBUG] Dependency collection stats: {ConflictMarker.analyzeTime=2, ConflictMarker.markTime=1, ConflictMarker.nodeCount=112, ConflictIdSorter.graphTime=2, ConflictIdSorter.topsortTime=0, ConflictIdSorter.conflictIdCount=39, ConflictIdSorter.conflictIdCycleCount=0, ConflictResolver.totalTime=13, ConflictResolver.conflictItemCount=95, DefaultDependencyCollector.collectTime=821, DefaultDependencyCollector.transformTime=24}
  </code></pre>