The issue was found on Ubuntu when building collectd with openjdk-21[1].

Building the following example:
---
#include <jni.h>

int main(){
    JavaVM *jvm; /* denotes a Java VM */
    JNIEnv *env; /* pointer to native method interface */
    JavaVMInitArgs vm_args; /* JDK/JRE 6 VM initialization arguments */
    JavaVMOption* options = new JavaVMOption[1];
    options[0].optionString = "-Djava.class.path=/usr/lib/java";
    vm_args.version = JNI_VERSION_1_6;
    vm_args.nOptions = 1;
    vm_args.options = options;
    vm_args.ignoreUnrecognized = false;
    /* load and initialize a Java VM, return a JNI interface
     * pointer in env */
    JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);
}
---

$g++ test.cpp -I/usr/lib/jvm/default-java/include -I/usr/lib/jvm/default-java/include/linux -L/usr/lib/jvm/default-java/lib/server -ljvm
...
fails with /usr/bin/ld: /usr/lib/jvm/default-java/lib/server/libjvm.so: undefined reference to `_Copy_conjoint_bytes'

JDK-8142362 removed the implementation of _Copy_conjoint_bytes but left the symbol declaration in, causing the symbol to be undefined:
 96657: 00000000 0 FUNC GLOBAL DEFAULT UND _Copy_conjoint_bytes

JDK-8017234 fixed the issue in master by removing the declaration.
openjdk-22 and openjdk-21 are still affected.

[1] https://bugs.launchpad.net/ubuntu/+source/collectd/+bug/2058966