I could solve one part of the build issues with Java 9 but I am stuck with
"/build/jboss-xnio-3.6.2/api/src/main/java/java/nio/channels/FileChannel.java:[19,1] package exists in another module: java.base " I have read about the new --patch-modules option but I am not sure if this is the right way. Renaming the package is probably the way forward. However upstream is still working on Java 9 support and I don't want to act prematurely. Let's see with what they will come up with. Hopefully it happens before Buster freezes.
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