bin/isabelle_java

 
   if [ -z "$JAVA_HOME" ]; then
     echo "Unknown JAVA_HOME -- Java unavailable" >&2
     exit 127
   else
+    unset ISABELLE_HOME
     unset CLASSPATH
     exec "$JAVA_HOME/bin/java" "${JAVA_ARGS[@]}" -classpath "$ISABELLE_CLASSPATH" "$@"
   fi
 }