Package: python3.2
Version: 3.2.2-4
Severity: important
Dear Maintainer,
In newer versions of Python, it appears pipes cannot be passed from one
subprocess
to another via subprocess.Popen calls; they are still closed even though the
close_fds
arg is specified as False.
I am appending a test script to illustrate the problem. Try running this with
different
versions of Python, and observe the difference: it works fine with 2.6 and 3.1,
and
fails with 2.7 and 3.2.
-- System Information:
Debian Release: wheezy/sid
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'oldstable'), (101, 'experimental')
Architecture: amd64 (x86_64)
Kernel: Linux 3.2.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_NZ.UTF-8, LC_CTYPE=en_NZ.UTF-8 (charmap=UTF-8) (ignored: LC_ALL
set to en_NZ.utf8)
Shell: /bin/sh linked to /bin/bash
Versions of packages python3.2 depends on:
ii libbz2-1.0 1.0.6-1
ii libc6 2.13-24
ii libdb5.1 5.1.29-1
ii libgcc1 1:4.6.2-12
ii libncursesw5 5.9-4
ii libreadline6 6.2-8
ii libsqlite3-0 3.7.9-3
ii libtinfo5 5.9-4
ii mime-support 3.51-1
ii python3.2-minimal 3.2.2-4
python3.2 recommends no packages.
Versions of packages python3.2 suggests:
pn binutils 2.22-5
pn python3.2-doc <none>
-- no debconf information
#+
# Demonstration of misbehaviour of close_fds arg to subprocess.Popen
# on certain versions of Python. This process creates two subprocesses,
# specifying that stdin of the first one is connected to a pipe. That
# pipe should be passed to the second process, but in some cases it's not.
#
# Try this script with various versions of Python, for example
#
# python2.6 test.py
# python2.7 test.py
# python3.1 test.py
# python3.2 test.py
#
# and note the differences in the output. Details on what to look for are
# below.
#
# Written 2012 February 1 by Lawrence D'Oliveiro <l...@geek-central.gen.nz>.
#-
import subprocess
child1 = subprocess.Popen \
(
args = ["bash", "-c", "sleep 5"],
shell = True,
stdin = subprocess.PIPE,
close_fds = True,
)
child2 = subprocess.Popen \
(
args =
[
"ls", "-l", "/dev/fd/",
],
close_fds = False,
shell = False,
)
# Example of correct output (e.g. Python versions 2.6 and 3.1):
# total 0
# lrwx------ 1 ldo users 64 Feb 1 09:00 0 -> /dev/pts/2
# lrwx------ 1 ldo users 64 Feb 1 09:00 1 -> /dev/pts/2
# lrwx------ 1 ldo users 64 Feb 1 09:00 2 -> /dev/pts/2
# lr-x------ 1 ldo users 64 Feb 1 09:00 3 -> /proc/2833/fd
# l-wx------ 1 ldo users 64 Feb 1 09:00 4 -> pipe:[714773]
#
# Example of incorrect output (e.g. Python versions 2.7 and 3.2):
# total 0
# lrwx------ 1 ldo users 64 Feb 1 09:03 0 -> /dev/pts/2
# lrwx------ 1 ldo users 64 Feb 1 09:03 1 -> /dev/pts/2
# lrwx------ 1 ldo users 64 Feb 1 09:03 2 -> /dev/pts/2
# lr-x------ 1 ldo users 64 Feb 1 09:03 3 -> /proc/3156/fd
#
# Note the pipe file descriptor is missing in the second case.
