Intermittent NoClassDefFoundError when running a maven/surefire build in jenkins

Question

We are building a large multi module Maven project on Jenkins, including running a large number of unit test.

Once every few builds the build fails on NoClassDefF

Answer 1

Try running the maven build without the -T 4.

The parallel builds feature in Maven 3 is still in the experimental stages, and it appears that there are known issues with thread safety in the plexus-utils library prior to version 2.0.5 - you're using version 1.5.1.

Edit:

Your problem is this dependency:

        
            org.apache.maven.surefire
            surefire-junit47
            ${testing.surefire.version}
        

surefire-junit47 depends on maven-surefire-common, which in turn depends on maven-artifact, which depends on plexus-utils-1.5.1. As stated above, this has known thread safety issues, which is likely what is causing your problems. I'm not sure what parts of the surefire-junit47 library you're using, but if switching to surefire-junit4 is an option, then that should solve your problem.

After looking at the docs for the surefire plugin a little more, it looks like you need the surefire-junit47 provider to run parallel tests. I'd try overriding plexus-utils to be version 2.0.5 and see if that works; otherwise, you can override the maven-artifact version to 3.0.3 or higher and see if that works.