Cannot debug pyside applications

[David Butler]

$ cat test.py
import PySide.QtCore
print "Import successful"

 This is what I expected to happen:
$ python2.7 test.py
Import successful

This is what happened
$ python2.7-dbg test.py
python2.7-dbg: ../Objects/object.c:65: _Py_AddToAllObjects: Assertion `(op->_ob_prev == ((void *)0)) == (op->_ob_next == ((void *)0))' failed.
Aborted (core dumped)

$ lsb_release -rd
Description: Ubuntu 12.04.2 LTS
Release: 12.04

$ apt-cache policy python-pyside
python-pyside:
  Installed: 1.1.0-1
  Candidate: 1.1.0-1
  Version table:
 *** 1.1.0-1 0
        990 http://us.archive.ubuntu.com/ubuntu/ precise/universe amd64 Packages
        100 /var/lib/dpkg/status

$ apt-cache policy python
python:
  Installed: 2.7.3-0ubuntu2
  Candidate: 2.7.3-0ubuntu2
  Version table:
 *** 2.7.3-0ubuntu2 0
        990 http://us.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status

$ apt-cache policy python-dbg
python-dbg:
  Installed: 2.7.3-0ubuntu2
  Candidate: 2.7.3-0ubuntu2
  Version table:
 *** 2.7.3-0ubuntu2 0
        990 http://us.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: python-pyside 1.1.0-1
ProcVersionSignature: Ubuntu 3.2.0-32.51-generic 3.2.30
Uname: Linux 3.2.0-32-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: amd64
Date: Tue May 21 10:55:48 2013
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: pyside
UpgradeStatus: No upgrade log present (probably fresh install)

[David Butler (w-daveb)]

#0 0x00007fbb265cd425 in __GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1 0x00007fbb265d0b8b in __GI_abort () at abort.c:91
#2 0x00007fbb265c60ee in __assert_fail_base (fmt=<optimized out>, assertion=0x5fd8d8 "(op->_ob_prev == ((void *)0)) == (op->_ob_next == ((void *)0))", file=0x5fd8c0 "../Objects/object.c", line=<optimized out>, function=<optimized out>)
    at assert.c:94
#3 0x00007fbb265c6192 in __GI___assert_fail (assertion=0x5fd8d8 "(op->_ob_prev == ((void *)0)) == (op->_ob_next == ((void *)0))", file=0x5fd8c0 "../Objects/object.c", line=65, function=0x5fe7b0 "_Py_AddToAllObjects") at assert.c:103
#4 0x0000000000487c78 in _Py_AddToAllObjects (op=<unknown at remote 0x7fbb252f2a00>, force=0) at ../Objects/object.c:65
#5 0x00000000004ba785 in PyType_Ready (type=0x7fbb252f2a00) at ../Objects/typeobject.c:3960
#6 0x00007fbb250d1900 in Shiboken::init() () from /usr/lib/x86_64-linux-gnu/libshiboken-python2.7.so.1.1
#7 0x00007fbb250df799 in Shiboken::Module::create(char const*, void*) () from /usr/lib/x86_64-linux-gnu/libshiboken-python2.7.so.1.1
#8 0x00007fbb25b85da9 in initQtCore () from /usr/lib/python2.7/dist-packages/PySide/QtCore.so
#9 0x0000000000547e2d in _PyImport_LoadDynamicModule (name=0x7fff65332a30 "PySide.QtCore", pathname=0x7fff65331940 "/usr/lib/python2.7/dist-packages/PySide/QtCore.so", fp=0x262abb0) at ../Python/importdl.c:53
#10 0x0000000000543de2 in load_module (name=0x7fff65332a30 "PySide.QtCore", fp=0x262abb0, pathname=0x7fff65331940 "/usr/lib/python2.7/dist-packages/PySide/QtCore.so", type=3, loader=0x0) at ../Python/import.c:1831
#11 0x0000000000545fee in import_submodule (mod=<module at remote 0x25f1d60>, subname=0x7fff65332a37 "QtCore", fullname=0x7fff65332a30 "PySide.QtCore") at ../Python/import.c:2595
#12 0x000000000054554d in load_next (mod=<module at remote 0x25f1d60>, altmod=<module at remote 0x25f1d60>, p_name=0x7fff653329f8, buf=0x7fff65332a30 "PySide.QtCore", p_buflen=0x7fff65332a08) at ../Python/import.c:2415
#13 0x00000000005447e2 in import_module_level (name=0x0, globals={'__builtins__': <module at remote 0x7fbb27cb1470>, '__name__': '__main__', '__file__': 'test.py', '__doc__': None, '__package__': None}, locals=
    {'__builtins__': <module at remote 0x7fbb27cb1470>, '__name__': '__main__', '__file__': 'test.py', '__doc__': None, '__package__': None}, fromlist=None, level=-1) at ../Python/import.c:2144
#14 0x0000000000544c68 in PyImport_ImportModuleLevel (name=0x25f1c3c "PySide.QtCore", globals={'__builtins__': <module at remote 0x7fbb27cb1470>, '__name__': '__main__', '__file__': 'test.py', '__doc__': None, '__package__': None},
    locals={'__builtins__': <module at remote 0x7fbb27cb1470>, '__name__': '__main__', '__file__': 'test.py', '__doc__': None, '__package__': None}, fromlist=None, level=-1) at ../Python/import.c:2188
#15 0x000000000051043b in builtin___import__ (self=0x0, args=('PySide.QtCore', {'__builtins__': <module at remote 0x7fbb27cb1470>, '__name__': '__main__', '__file__': 'test.py', '__doc__': None, '__package__': None}, {...}, None), kwds=
    0x0) at ../Python/bltinmodule.c:49
#16 0x0000000000486804 in PyCFunction_Call (func=<built-in functio...

[David Butler (w-daveb)]

I asked on the pyside mailing list, http://permalink.gmane.org/gmane.comp.lib.qt.pyside/4568

it seems that its an issue with using a pydebug interpreter and a non debug version of pyside. I am currently looking into this PPA (https://launchpad.net/~forger/+archive/pyside-debug) to see if it is a workaround

[David Butler (w-daveb)]

using the python-pyside version found in the PPA (https://launchpad.net/~forger/+archive/pyside-debug) solved the issue. perhaps ubuntu would consider maintaining a debug version of this library

[Julian Taylor (jtaylor)]

pyside is maintained in debian
having a debug build makes sense and the same crash occurs in unstable, please file a bug in debian:
https://wiki.ubuntu.com/Debian/Bugs