title: Can't get correct package from Nexus? error in "mvn help:effective-settings"
body: <p>I use nexus opensource version maven 2.2.1</p>
  
  <p>When I type "mvn help:effective-settings", i got the error below</p>
  
  <pre><code>[INFO] Scanning for projects...
  [INFO] Searching repository for plugin with prefix: 'help'.
  [INFO] ------------------------------------------------------------------------
  [ERROR] BUILD ERROR
  [INFO] ------------------------------------------------------------------------
  [INFO] Error building POM (may not be this project's POM).
  
  Project ID: org.apache.maven.plugins:maven-help-plugin
  
  Reason: Error getting POM for 'org.apache.maven.plugins:maven-help-plugin' from the   repository: Failed to resolve artifact, possibly due to a repository list that is not appropriately equipped for this artifact's metadata.
   org.apache.maven.plugins:maven-help-plugin:pom:2.2-SNAPSHOT
  
  from the specified remote repositories:
   Nexus (http://192.168.56.191:8081/nexus/content/groups/public)
  
  for project org.apache.maven.plugins:maven-help-plugin
  </code></pre>
  
  <p>When I check the local repository under ~.m2\repository\org\apache\maven\plugins\maven-help-plugin</p>
  
  <p>It has a file maven-metadata-central.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;metadata&gt;
    &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
    &lt;artifactId&gt;maven-help-plugin&lt;/artifactId&gt;
    &lt;versioning&gt;
      &lt;latest&gt;2.2-SNAPSHOT&lt;/latest&gt;
      &lt;release&gt;2.1.1&lt;/release&gt;
      &lt;versions&gt;
        &lt;version&gt;2.0&lt;/version&gt;
        &lt;version&gt;2.0.1&lt;/version&gt;
        &lt;version&gt;2.0.2&lt;/version&gt;
        &lt;version&gt;2.1&lt;/version&gt;
        &lt;version&gt;2.1.1&lt;/version&gt;
        &lt;version&gt;2.2-SNAPSHOT&lt;/version&gt;
      &lt;/versions&gt;
     &lt;lastUpdated&gt;20100519065440&lt;/lastUpdated&gt;
    &lt;/versioning&gt;
  &lt;/metadata&gt;
  </code></pre>
  
  <p>And I can't find any jar files under directory, what's wrong with nexus server ? I can't easily find support information from nexus.</p>
  
  <p>Any hints</p>