Message12704

It happens when you compile against an API in which ByteBuffer provides an implementation of clear() that declares it returns ByteBuffer (this seems to be the case from JDK 9), but you run on a JVM where ByteBuffer declares that clear() returns Buffer.

https://github.com/eclipse/jetty.project/issues/3244

The reason JRuby need the backport patch is, if I've understood correctly, that they compile on Java 9+ (to get various compiler features) but want to be able run on 8.

Maybe your IDE is compiling for you using a different profile from the ant build. Does this happen if you run "ant clean developer-build" at the prompt where javac means Java 8?

However, the first exhibit in the issue, where a Java 10 JVM is unable to find java.nio.ByteBuffer.clear()Ljava/nio/ByteBuffer; makes no sense to me. Has something messed up your JVM boot classpath, JYTHON_OPTS or similar "invisible" options?

If I set Java 11 and run a clean build, I get exactly that dump only once I reduce the environment to 8.