Runtime class loading causes crash on 1.52.0; DD Java Agent clashes with OTel Agent JAR

Start with the provided GroovyClassLoader reproduction and run it with both the OTel agent and DD Agent 1.52.0 in JAVA_OPTS, then compare behavior with DD Agent 1.51.0 and agent ordering. Done means runtime Groovy class loading no longer crashes with the supported agent combination, with the expected behavior verified against the reported NoClassDefFoundError.

Tracer Version(s)

1.52.0

Java Version(s)

21.0.4

JVM Vendor

Other (please specify in comments)

Bug Report

Hi,

My JDK 21 application started crashing at runtime after pulling in the latest DD Java Agent JAR (v1.52.0). At runtime, I am using Groovy to dynamically load a set of classes, and I saw the following error:

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
General error during instruction selection: java.lang.NoClassDefFoundError: io/opentelemetry/javaagent/instrumentation/internal/classloader/BootstrapPackagesHelper
java.lang.RuntimeException: java.lang.NoClassDefFoundError: io/opentelemetry/javaagent/instrumentation/internal/classloader/BootstrapPackagesHelper
	at org.codehaus.groovy.control.CompilationUnit$IPrimaryClassNodeOperation.doPhaseOperation(CompilationUnit.java:972)
	at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:692)
	at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:666)
	at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:365)
	at groovy.lang.GroovyClassLoader.lambda$parseClass$2(GroovyClassLoader.java:314)
	at org.codehaus.groovy.runtime.memoize.StampedCommonCache.compute(StampedCommonCache.java:163)
	at org.codehaus.groovy.runtime.memoize.StampedCommonCache.getAndPut(StampedCommonCache.java:154)
	at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:314)
	at groovy.lang.GroovyShell.parseClass(GroovyShell.java:572)
	at groovy.lang.GroovyShell.parse(GroovyShell.java:585)
	at groovy.lang.GroovyShell.parse(GroovyShell.java:564)
	at groovy.lang.GroovyShell.parse(GroovyShell.java:552)
	at groovy.lang.GroovyShell.evaluate(GroovyShell.java:534)
        <REDACTED>
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.springframework.boot.loader.launch.Launcher.launch(Launcher.java:102)
	at org.springframework.boot.loader.launch.Launcher.launch(Launcher.java:64)
	at org.springframework.boot.loader.launch.JarLauncher.main(JarLauncher.java:40)
Caused by: java.lang.NoClassDefFoundError: io/opentelemetry/javaagent/instrumentation/internal/classloader/BootstrapPackagesHelper
	at groovy.lang.GroovyClassLoader$InnerLoader.loadClass(GroovyClassLoader.java:585)
	at java.base/java.lang.ClassLoader.defineClass1(Native Method)
	at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1027)
	at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:150)
	at groovy.lang.GroovyClassLoader.access$400(GroovyClassLoader.java:90)
	at groovy.lang.GroovyClassLoader$ClassCollector.createClass(GroovyClassLoader.java:682)
	at groovy.lang.GroovyClassLoader$ClassCollector.onClassNode(GroovyClassLoader.java:699)
	at groovy.lang.GroovyClassLoader$ClassCollector.call(GroovyClassLoader.java:704)
	at org.codehaus.groovy.control.CompilationUnit$3.call(CompilationUnit.java:806)
	at org.codehaus.groovy.control.CompilationUnit$IPrimaryClassNodeOperation.doPhaseOperation(CompilationUnit.java:938)
	... 21 more
Caused by: java.lang.ClassNotFoundException: io.opentelemetry.javaagent.instrumentation.internal.classloader.BootstrapPackagesHelper
	... 31 more

I am using both the DD Agent JAR as well as the OTel Agent JAR in my Application. The DD Agent is listed first in my Java Opts, and hence takes priority. This was not happening on earlier versions of the DD Agent JAR.

As a work-around, I have reverted to use v1.51.0 and the issue is resolved there. I may also consider trying to re-order the agents, such that the OTel Agent JAR takes precedence. However, curious what may have changed in the DD Agent JAR in this release, which would have caused this. Thanks!

Expected Behavior

Application starts up, with no issue loading classes at runtime.

Reproduction Code

			ClassLoader appClassLoader = MyApplication.class.getClassLoader();
			GroovyClassLoader groovyClassLoader = new GroovyClassLoader(appClassLoader);
			GroovyShell shell = new GroovyShell(groovyClassLoader, binding);

			PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
			Resource[] resources = resolver.getResources("classpath:*.groovy");
			Arrays.sort(resources, Comparator.comparing(Resource::getFilename));
			for (Resource resource: resources) {
				Reader reader = new InputStreamReader(resource.getInputStream());
				shell.evaluate(reader, resource.getFilename());
			}

And, ensure that the JVM JAVA_OPTS has both the OTel (latest) and DD Agent (1.52.0) JARs.