java.lang.NullPointerException
        at org.python.core.Py.flushLine(Py.java:1310)
        at org.python.core.Py.displayException(Py.java:1003)
        at org.python.core.PyException.printStackTrace(PyException.java:79)
        at org.python.core.PyException.toString(PyException.java:98)
        at org.netbeans.lib.uihandler.LogFormatter.printThrown(LogFormatter.java:211)
        at org.netbeans.lib.uihandler.LogFormatter.format(LogFormatter.java:329)
        at org.netbeans.lib.uihandler.LogRecords.write(LogRecords.java:84)
        at org.netbeans.modules.uihandler.Installer.writeOut(Installer.java:405)
        at org.netbeans.modules.uihandler.UIHandler$1WriteOut.run(UIHandler.java:105)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)