[ERROR] Failed to execute goal org.jacoco:jacoco-maven-plugin:0.8.7:report (default-cli) on project http: 
An error has occurred in JaCoCo report generation. Error while creating report: 
Error while analyzing /srv/data/jenkins/workspace/my-project/http/target/classes/openejb-client.jar.pack.gz@javax/xml/ws/EndpointReference.class. 
Can't add different class with same name: javax/xml/ws/EndpointReference -> [Help 1]
Wanted Behaviour
As per #661 (comment), I understand that Jacoco Maven plugin only analyzes the content of target/classes. Classes stored in jars found in target/classes will never end up in the JVM classpath.
Therefore, I don't see any reason to let Jacoco scan for zip, gz or pack200 files in the context of the Maven plugin. In this context, I think that analysis should be limited to plain class files (out of any archive).
I guess that would mean allowing to pass a detector type filter to Analyzer.analyzeAll method:
public int analyzeAll(final InputStream input, final String location)
			throws IOException {
		final ContentTypeDetector detector;
		try {
			detector = new ContentTypeDetector(input);
		} catch (final IOException e) {
			throw analyzerError(location, e);
		switch (detector.getType()) {
		case ContentTypeDetector.CLASSFILE:
			analyzeClass(detector.getInputStream(), location);
			return 1;
		case ContentTypeDetector.ZIPFILE:
			return analyzeZip(detector.getInputStream(), location);
		case ContentTypeDetector.GZFILE:
			return analyzeGzip(detector.getInputStream(), location);
		case ContentTypeDetector.PACK200FILE:
			return analyzePack200(detector.getInputStream(), location);
		default:
			return 0;
Possible Workarounds
<plugin>
        <groupId>org.jacoco</groupId>
        <artifactId>jacoco-maven-plugin</artifactId>
        <version>0.8.7</version>
        <configuration>
          <excludes>
            <exclude>**/*.jar.pack.gz</exclude>
            <exclude>**/*.jar.pack</exclude>
            <exclude>**/*.jar</exclude>
            <exclude>**/*.zip</exclude>
          </excludes>
        </configuration>
      </plugin>
      changed the title
Jacoco maven plugin should exclude zip, gz and pack200 file from analysis
Jacoco maven plugin should exclude zip, gz and pack200 files from analysis
    Nov 16, 2021