=====================
From: David S. <davidschein <at> alumni.tufts.edu>
Subject: subprocess problem on Windows in IDLE and PythonWin
Newsgroups: gmane.comp.python.general
Date: Wed, 16 Feb 2005 02:05:24 +0000


Python 2.4 on Windows XP
In the python command-line the following works fine:

>>> from subprocess import *
>>> p = Popen('dir', stdout=PIPE)

>From within IDLE or PythonWin I get the following exception:

Traceback (most recent call last):
  File "<pyshell#13>", line 1, in -toplevel-
    p = Popen('dir', stdout=PIPE)
  File "c:\python24\lib\subprocess.py", line 545, in __init__
    (p2cread, p2cwrite,
  File "c:\python24\lib\subprocess.py", line 605, in _get_handles
    p2cread = self._make_inheritable(p2cread)
  File "c:\python24\lib\subprocess.py", line 646, in 
_make_inheritable
    DUPLICATE_SAME_ACCESS)
TypeError: an integer is required

Note it works fine on Linux also.  I tested it with 
>>> p = Popen('ls', stdout=PIPE)
... and had no trouble.

===========

I (KBK) can duplicate this on W2K using 2.4.  If I run IDLE with the -n 
switch (no subprocess) the error doesn't occur.

Unfortunately, I can't debug it because I don't have the necessary
tools on Windows.  It appears that the problem is in 
_subprocess.c:sp_DuplicateHandle(), likely that PyArg_ParseTuple()
is OK but the failure occurs in the call to DuplicateHandle().

All the args to sp_DuplicateHandle() seem to be the right type.
DUPLICATE_SAME_ACCESS is an integer, value 2

To find out what's going on, it would seem necessary to attach a
windows debugger to IDLE's subprocess (not the IDLE GUI).  Let
me know if I can help.