more robust Isabelle_System.rm_fifo: avoid external bash invocation, which might not work in JVM shutdown phase (due to Runtime.addShutdownHook);
more robust Isabelle_System.rm_fifo: avoid external bash invocation, which might not work in JVM shutdown phase (due to Runtime.addShutdownHook);

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle