[MPMD-325] Could not find class due to IncompatibleClassChangeError warning

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.15.0
• Fix Version/s: 3.16.0
• Component/s: PMD
• Environment: - maven-pmd-plugin: 3.15.0 (PMD 6.38.0) ; - OpenJDK 8, 11, 16 ; - Maven 3.8.1 / 3.8.2
• External issue URL: https://github.com/pmd/pmd/issues/3502
• Assignee: Andreas Dangel
• Reporter: e6a
• Created: 17/Sep/21 08:25
• Updated: 30/Sep/21 13:42
• Resolved: 30/Sep/21 13:42

Description

After upgrading to maven-pmd-plugin 3.15, the analysis shows a "Could not find class [...]" warning for each scanned file. Earlier versions up to 3.14 (= pmd 6.29.0) aren't affected.

Exception Stacktrace:

[INFO] PMD version: 6.38.0
[WARNING] Could not find class <PROJECT CLASS>, due to: java.lang.IncompatibleClassChangeError: class net.sourceforge.pmd.lang.java.typeresolution.visitors.PMDASMVisitor has interface org.objectweb.asm.ClassVisitor as super class

The warning message appears for each class in the project.

Code Sample demonstrating the issue:

<!-- pom.xml -->
[...]
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-pmd-plugin</artifactId>
                <version>3.15.0</version>
                <configuration>
                    <linkXRef>false</linkXRef>
                </configuration>
            </plugin>
        </plugins>
    </build>
[...]

Steps to reproduce:

1. Setup a Maven project with maven-pmd-plugin 3.15.0 with something to analyse
2. mvn clean verify pmd:pmd
3. The mentioned warning appears

Workaround:

Add dependency to org.ow2.asm for the pmd plugin:

<dependency>
    <groupId>org.ow2.asm</groupId>
    <artifactId>asm</artifactId>
    <version>9.2</version>
</dependency>

---

Original issue reported to the pmd project.

Issue Links

• is blocked by: MPMD-326 Set Maven 3.1.1 as minimum version
• links to: GitHub Pull Request #47