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IDProjectCategoryView StatusDate SubmittedLast Update
0000853XdebugUncategorizedpublic2012-06-15 21:542012-06-25 18:00
Reporterfidian Assigned To 
PrioritynormalSeveritycrashReproducibilityalways
Status resolvedResolutionunable to reproduce 
PlatformLinuxOSUbuntuOS VersionVarious
Product Version2.2.0 
Summary0000853: Segmentation fault when running phpunit
Description

I have tried versions 2.1.0 and 2.2.0. The newer version gives either a "Segmentation fault" or "Illegal instruction" when running a set of tests for my software, which is closed source. Running just that test or the suite of tests doesn't create the problem; only when I run all of the tests in the directory at once, so I know that there's something more complex going on here.

Currently I am seeing the problems in our Amazon instances - c1.medium amd64 Ubuntu natty. They use PHP 5.3.6 (Ubuntu's package) as well as 5.3.13 (team-mayhem/ppa - my updated version). The xdebug from Ubuntu (2.1.0) works and team-mayhem/ppa's (2.2.0) fails. Without changing anything else on the system, just switching xdebug packages caused the problem to happen or to go away.

I've bisected your git repository and narrowed this down to commit 72e60fdc5960cf89e2e4fd5c6477b83600d5b8b2 (SVN Rev: 3391) where you fix bug 0000654 by bringing back three lines of code.

I can't really give you our codebase for you to diagnose the problem. I also don't have the problem narrowed down to a simple, repeatable test script that I could hand over. The ickiest solution for me would be to replicate everything we do, chopping out parts, and then hopefully whittling down the code to whatever combination triggers the problem. A far better solution would be to seek your assistance and add debugging information in the right spots so you can find out why things are breaking.

Would you have any idea why those three lines of code would force segmentation faults?

TagsNo tags attached.
Operating SystemUbuntu
PHP Version5.3.13

Activities

derick

2012-06-16 07:12

administrator   ~0002259

Can you run phpunit through GDB?

You run that with:

export USE_ZEND_ALLOC=0
gdb --args php which phppunit ...your other php unit options...

On the GDB prompt:
run
and when it crashes:
bt full

fidian

2012-06-16 14:46

reporter   ~0002260

Last edited: 2012-06-16 14:47

This is with xdebug compiled at commit 72e60fdc5960cf89e2e4fd5c6477b83600d5b8b2. If you need it at master's HEAD, let me know.

See attachment gdb.txt

derick

2012-06-16 14:54

administrator   ~0002261

This trace shows it is not actually crashing in Xdebug st all, but in normal PHP. I would think that if you would disable Xdebug with the USE_ZEND_ALLOC=0 still active or will crash as well. Perhaps you can try running it without Xdebug like that?

fidian

2012-06-18 00:19

reporter   ~0002262

I rebooted the machine, then ran the following commands:

echo "$USE_ZEND_ALLOC"
gdb --args php which phpunit .

Pass

export USE_ZEND_ALLOC=0
echo "$USE_ZEND_ALLOC"
gdb --args php which phpunit .

Fail

export USE_ZEND_ALLOC=
echo "$USE_ZEND_ALLOC"
gdb --args php which phpunit .

Fail

See log.txt for further information. Again, the weird part is that one line of code in xdebug - if I comment it out, no more segmentation faults.

I'll work on whittling down the tests to see exactly what's causing it. It might take a while. Do you have any other ideas for things I can try?

fidian

2012-06-22 13:44

reporter   ~0002267

I'm running tests again and am unable to get consistent results. I am no longer certain that changing xdebug really affects anything. I suspect that the combination of PHP and xdebug do trigger an effect sometimes, but until I can nail this down I won't waste your time.

Please close this bug. If I can narrow things down and figure out where the breakage starts, I may open another bug (but it is really looking like PHP at the moment). Sorry to waste your time.

derick

2012-06-25 18:00

administrator   ~0002275

No worries, and feel free to reopen this if you have more info and/or can reproduce it.