Question

I have a project that uses the maven-assembly-plugin to create source and binary tar and zip files for download. However, whenever I try to build the bin assembly it fails with an error that says “A tar file cannot include itself.”

I can reproduce this problem with a minimal Maven project created with the maven-archetype-plugin and adding the following to the pom.xml:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <version>2.2</version>
    <configuration>
      <descriptorRefs>
        <descriptorRef>src</descriptorRef>
        <descriptorRef>bin</descriptorRef>
      </descriptorRefs>
      <outputDirectory>${project.build.directory}/site/downloads</outputDirectory>
    </configuration>
    <executions>
      <execution>
        <phase>site</phase>
        <goals>
          <goal>single</goal>
        </goals>
      </execution>
    </executions>
  </plugin>

With this plugin declaration in place I get the above-mentioned error message if I execute either “mvn site” or “mvn assembly:assembly”.

Does anyone have any idea why this isn’t working?

I’d be happy to provide any other information needed to help diagnose the problem.

Answer 1

It looks like there is a problem with version 2.2 of the Maven Assembly Plugin, your snippet works with the version 2.1 of the plugin.

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <version>2.1</version>
    <configuration>
      <descriptorRefs>
        <descriptorRef>src</descriptorRef>
        <descriptorRef>bin</descriptorRef>
      </descriptorRefs>
      <outputDirectory>${project.build.directory}/site/downloads</outputDirectory>
    </configuration>
    <executions>
      <execution>
        <phase>site</phase>
        <goals>
          <goal>single</goal>
        </goals>
      </execution>
    </executions>
  </plugin>

I didn’t check Jira for an existing issue. If you can’t find any, it would be nice to raise a new one.