silent installer issue?

Hi, when I try to do a silent install on Linux (using OpenJDK8) I see 
this error.
Despite the error the installation seems to be successful.
Is this a know issue?

# java -jar jython-installer-2.7.0.jar -s -d jython
Performing silent installation
  10 %
  20 %
  30 %
  40 %
  50 %
  60 %
  70 %
Generating start scripts ...
Installing pip and setuptools
  90 %
java.io.IOException: Cannot run program "jython/bin/jython" (in 
directory "jython/bin"): error=20, Not a directory
     at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
     at org.python.util.install.ChildProcess.run(ChildProcess.java:272)
     at 
org.python.util.install.JarInstaller.ensurepip(JarInstaller.java:187)
     at org.python.util.install.JarInstaller.inflate(JarInstaller.java:152)
     at 
org.python.util.install.ConsoleInstaller.install(ConsoleInstaller.java:66)
     at 
org.python.util.install.Installation.internalMain(Installation.java:389)
     at org.python.util.install.Installation.main(Installation.java:43)
Caused by: java.io.IOException: error=20, Not a directory
     at java.lang.UNIXProcess.forkAndExec(Native Method)
     at java.lang.UNIXProcess.<init>(UNIXProcess.java:248)
     at java.lang.ProcessImpl.start(ProcessImpl.java:134)
     at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
     ... 6 more
  100 %
Congratulations! You successfully installed Jython 2.7.0 to directory 
/jython.

Thanks
Tim

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