title: NullPointerException archetype:crawl
body: <p>I'm trying to discover the archtypes installed in my local repository. I read this is possible run the following command:</p>
  
  <blockquote>
    <p>mvn archetype:crawl</p>
  </blockquote>
  
  <p>Now when I run this command I get this error:</p>
  
  <pre><code>    [ERROR] Failed to execute goal org.apache.maven.plugins:maven-archetype-plugin:2.2:crawl (default-cli) on project standalone-pom: Execution default-cli of goal org.apache.maven.plugins:maven-archetype-plugin:2.2:crawl failed. NullPointerException -&gt; [Help 1]
  org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-archetype-plugin:2.2:crawl (default-cli) on project standalone-pom: Execution default-cli of goal org.apache.maven.plugins:maven-archetype-plugin:2.2:crawl failed.
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:224)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
      at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
      at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
      at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
      at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
      at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:317)
      at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:152)
      at org.apache.maven.cli.MavenCli.execute(MavenCli.java:555)
      at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:214)
      at org.apache.maven.cli.MavenCli.main(MavenCli.java:158)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:606)
      at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
      at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
      at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
      at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
  Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-cli of goal org.apache.maven.plugins:maven-archetype-plugin:2.2:crawl failed.
      at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:115)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
      ... 19 more
  Caused by: java.lang.NullPointerException
      at org.apache.maven.archetype.common.DefaultArchetypeArtifactManager.closeZipFile(DefaultArchetypeArtifactManager.java:584)
      at org.apache.maven.archetype.common.DefaultArchetypeArtifactManager.isFileSetArchetype(DefaultArchetypeArtifactManager.java:196)
      at org.apache.maven.archetype.repositorycrawler.DefaultRepositoryCrawler.crawl(DefaultRepositoryCrawler.java:72)
      at org.apache.maven.archetype.mojos.CrawlRepositoryMojo.execute(CrawlRepositoryMojo.java:70)
      at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:106)
      ... 20 more
  </code></pre>