Message10855

I tried to execute "jump" command of pdb lib. I'm using Jython (in a Java application). Command comes with this error:
Traceback (most recent call last):
  File "C:\pdb_jump.py", line 20, in <module>
    result = []
  File "C:\jython\Lib\bdb.py", line 49, in trace_dispatch
    return self.dispatch_line(frame)
  File "C:\jython\Lib\bdb.py", line 67, in dispatch_line
    self.user_line(frame)
  File "C:\jython\Lib\pdb.py", line 158, in user_line
    self.interaction(frame, None)
  File "C:\jython\Lib\pdb.py", line 210, in interaction
    self.cmdloop()
  File "C:\jython\Lib\cmd.py", line 142, in cmdloop
    stop = self.onecmd(line)
  File "C:\jython\Lib\pdb.py", line 279, in onecmd
    return cmd.Cmd.onecmd(self, line)
  File "C:\jython\Lib\cmd.py", line 221, in onecmd
    return func(arg)
  File "C:\jython\Lib\pdb.py", line 705, in do_jump
    self.curframe.f_lineno = arg
  File "C:\jython\Lib\pdb.py", line 705, in do_jump
    self.curframe.f_lineno = arg
TypeError: readonly attribute
It seems "jump" command does not work. arg type is integer and this value cannot be set to "self.curframe.f_lineno".
Java version: 1.8 64-bit, Jython versin: 2.7