pdb doesn't respond after pdb.set_trace() call

Question

I have parent process calling its child. I've put import pdb; pdb.set_trace() into the child process code.

When I launch the parent with python -m pdb parent.py it's getting frozen. The debugger doesn't respond to any command I type. But when I hit quit or continue it does exits code.

It looks like pdb works, but doesn't produce any output.

$ python -m pdb parent.py
n -m pdb parent.py
> d:\scripts\parent.py(53)<module>()
-> '''
(Pdb) c

It stops responding now.

According to the trace I get after interruption, it was standing at the line just after the pdb.set_trace() call.

>>>>>>>>>>>>>[2013.06.13-10:02:06] : accessed by child.py
Traceback (most recent call last):
File "child.py", line 40, in <module>
    sys.stderr = open(Definition_h.ErrLog, 'a', 0, encoding=Definition_h.utf8)
File "d:\scripts\Definition_h.py", line 863, in unicodeOpen
    def unicodeOpen(*args, **kwargs):
File "C:\Program Files (x86)\Python 2.5.4\lib\bdb.py", line 50, in trace_dispatch
    return self.dispatch_call(frame, arg)
File "C:\Program Files (x86)\Python 2.5.4\lib\bdb.py", line 79, in dispatch_call
    self.user_call(frame, arg)
File "C:\Program Files (x86)\Python 2.5.4\lib\pdb.py", line 134, in user_call
    self.interaction(frame, None)
File "C:\Program Files (x86)\Python 2.5.4\lib\pdb.py", line 187, in interaction
    self.cmdloop()
File "C:\Program Files (x86)\Python 2.5.4\lib\cmd.py", line 148, in cmdloop
    import readline
KeyboardInterrupt: !!!<unprintable KeyboardInterrupt object>
Error in sys.excepthook:

Answer 1

Actually the problem was that my code was redirecting sys.stdout to the log file