[ python-Bugs-1063937 ] Random core dumps
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Tue Nov 15 07:55:18 CET 2005
Bugs item #1063937, was opened at 2004-11-10 08:50
Message generated for change (Comment added) made by nnorwitz
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Category: Python Interpreter Core
Group: Python 2.2.3
>Status: Closed
>Resolution: Works For Me
>Priority: 5
Submitted By: munder12 (munder12)
>Assigned to: Neal Norwitz (nnorwitz)
Summary: Random core dumps
Initial Comment:
I have narrowed it down as far as I can by continuing
to make the problem simpler and simpler but where it
still core dumps.
The way this is set up is the following:
pytest2.py and pytest.py are in the same directory.
pytest3.py is in PYTHONPATH where PYTHONPATH is
<abs_path>/BASE:<abs_path>/SUP (pytest3.py is in BASE).
Run ./pytest2.py several times.
This current problem core dumps on average about 2
times every 5 runs.
I have attached a file that has the Python listings as
well as the gdb traceback.
This is running under Fedora Core 1 with:
Python 2.2.3 (#1, Oct 15 2003, 23:33:35)
[GCC 3.3.1 20030930 (Red Hat Linux 3.3.1-6)] on linux2
Thank you,
Mark
PS Strangely enough the comments in pytest.py seem to
actually increase the frequency of core dumps.
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>Comment By: Neal Norwitz (nnorwitz)
Date: 2005-11-14 22:55
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munder12, if you are still having problems let us know. I'm
closing this as not reproducible.
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Comment By: Reinhold Birkenfeld (birkenfeld)
Date: 2005-10-03 02:15
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I'd say that it can be closed. As mwh says: "If Python 2.4b2
cored 25% of the time it was launched, someone else would
have noticed by now :)"
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Comment By: Neal Norwitz (nnorwitz)
Date: 2005-10-02 23:42
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I can't reproduce on current CVS (2.5). Can anyone
reproduce this now? Should this be closed?
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Comment By: Nick Coghlan (ncoghlan)
Date: 2004-11-23 01:15
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I'm not sure it's relevant, but I once had a similar problem
with Python flakiness that turned out to be due to some old
.pyc files lying around (this was Fedora Core 3-test 1, and
the offending files were in my Python CVS build directory).
For whatever reason, Python wasn't picking up the version
mismatch and was trying to use the old .pyc files. Seg
faults abounded as a result.
One thought: could root ownership of pre-generated .pyc's
have that effect? (I don't know how Python reacts if it
can't delete the .pyc's)
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Comment By: munder12 (munder12)
Date: 2004-11-17 09:00
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I have written a program in C that just opens and closes a
file repeatedly. It appears to work fine. But, there
appears to be much more that Python is doing behind the
scenes than what my script is explicitly directing (open and
close the file). Since I'm not sure what all OS related
calls Python is making when opening, say, "site.py," I'm not
quite sure how I can write a C code that mimics what Python
is doing.
It may well be that the OS is the culprit. However, it also
could be that, in the Python code itself, some error
checking is not being performed on all OS calls as they
should be since they so rarely fail on a mjority of OS's.
Or, extra try...catch blocks maybe could be added to retry
the OS call(s) that is "incorrectly" failing on Fedora Core
1 so that Python maintains its portability with (hopefully)
minimal speed impact.
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Comment By: Tim Peters (tim_one)
Date: 2004-11-16 16:54
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At this point, it would be prudent to write the same kind of
program in straight C, and test that. The more you find out,
the less it appears that Python has something to do with
what you're seeing. Note that it's not unusual to discover
OS, compiler, and platform C library bugs by running Python
programs, simply because Python builds on all of them.
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Comment By: munder12 (munder12)
Date: 2004-11-16 16:47
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It is 2 times out of 8 runs of the main script. Actually, that is
2 cores out of 1600 runs of the script that really cores. It
does seem to be localized to Fedora Core 1. Fedora Core 2,
Win 2000, Win XP, and Mandrake 9 on similar hardware do not
have the problem with these scripts.
The Python 2.4b2 is straight out of the tarball (compiled and
installed cleanly). The core dumps occur randomly with
posixpath.py, site.py, etc. and at different stages (robject()
and within fstat() (from /usr/include/sys/stat.h)).
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Comment By: Michael Hudson (mwh)
Date: 2004-11-16 00:38
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Hmm. The traceback shows that it's dumping core while loading
the site.pyc file from the disk. This happens before Python begins
executing whatever code you've asked it to. You could try
deleting the site.pyc file and see if that makes any difference, or
running python -S.
I still think there must be something odd about your setup. If
Python 2.4b2 cored 25% of the time it was launched, someone
else would have noticed by now :)
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Comment By: munder12 (munder12)
Date: 2004-11-11 08:05
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I have checked out and built Python 2.4b2. It still core
dumps on these same files but it now takes on average about
8 runs to get 2 cores.
I will attach the 2.4b2 core traceback.
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Comment By: Michael Hudson (mwh)
Date: 2004-11-11 07:34
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Uh, if that tiny thing cores, I'm very much inclined to
believe there's something flaky in your setup.
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Comment By: munder12 (munder12)
Date: 2004-11-11 07:25
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I have played some more with the setup. Now only pytest2.py
and pytest.py need to be present in same directory.
Running pytest2.py will randomly cause core dumps coming
from pytest.py.
If you run pytest.py enough times directly it also will
randomly core.
I have attached pytest.py and pytest2.py.
I have not tried with any other version of Python yet.
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Comment By: Michael Hudson (mwh)
Date: 2004-11-11 06:47
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Have you tried a more recent Python?
I'm finding decoding your report (attempting to reproduce) a
little challenging. Could you upload a tarball containing a
shell script driver or something?
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