Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-06 Thread Kovid Goyal
Since it seems to be a fix, which indicates the issue is object ownership/lifetime, you can try an approach that avoids the warning. For example, dont give item1 a parent, instead add it to the scene, and when deleting item0 add code to manually delete item1. You can also try using the API in ht

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-06 Thread Lee Harr
>> The strangest part is that if I manually add item1 to the scene >> (should not be needed since the child is automatically added when >> the parent is added) I do not get the segfault. > From the description of the OPs problem I'd guess that it is > an object lifetime issue. Registering the ch

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-05 Thread Mathias . Born
On 05.01.2013, 22:58:28 Andreas Pakulat wrote: > Hi, > Am Samstag, 5. Januar 2013 schrieb : > On 05.01.2013, 16:50:29 Andreas Pakulat wrote: > [...] >> Often a segfault is caused by using a pointer (in C++) which points to >> a memory location thats not valid anymore, for example because the >> ob

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-05 Thread Andreas Pakulat
Hi, Am Samstag, 5. Januar 2013 schrieb : > On 05.01.2013, 16:50:29 Andreas Pakulat wrote: > [...] > > Often a segfault is caused by using a pointer (in C++) which points to > > a memory location thats not valid anymore, for example because the > > object has been deleted already. In the context o

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-05 Thread Lee Harr
First up, thanks again to those who are helping. I think I am getting a better handle on the problem. I am using: Ubuntu 12.10 Python 3.2.3 Qt 4.8.2 PyQt 4.9.3 I also have the ubuntu -dbg packages: python3-dbg python3-pyqt4-dbg Do I need to run my program with python3-dbg? I tried generatin

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-05 Thread Erik Janssens
Here are some things regarding detecting and preventing segfaults I've once written down for my own reference : http://python-camelot.s3.amazonaws.com/gpl/release/pyqt/doc/advanced/debug.html http://python-camelot.s3.amazonaws.com/gpl/release/pyqt/doc/advanced/development.html I have not seen an

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-05 Thread Kovid Goyal
A few places. Not PyQt's fault. It's not possible to reconcile object lifetime issues completely robustly between two different object systems over which you have very limited control. Here's the last example that bit me (this segfaults on linux, not other OSes). python -c "from PyQt4.Qt import

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-05 Thread Mathias . Born
On 05.01.2013, 16:50:29 Andreas Pakulat wrote: [...] > Often a segfault is caused by using a pointer (in C++) which points to > a memory location thats not valid anymore, for example because the > object has been deleted already. In the context of PyQt this can > happen when you stop keeping refere

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-05 Thread Andreas Pakulat
Hi, On Sat, Jan 5, 2013 at 4:09 PM, Lee Harr wrote: >> I tried pynguin-0.12.zip on Windows7, python 2.7, PyQt 4.8.4 32bit, >> and I could run "go()" many times without any crashes or warnings. >> However, there appears to be no "tournament" function. > > Thanks for taking your time on this, but t

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-05 Thread Lee Harr
> I tried pynguin-0.12.zip on Windows7, python 2.7, PyQt 4.8.4 32bit, > and I could run "go()" many times without any crashes or warnings. > However, there appears to be no "tournament" function. Thanks for taking your time on this, but the problem is only in the development sources. I am doing m

Re: [PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-05 Thread Mathias . Born
Lee, I tried pynguin-0.12.zip on Windows7, python 2.7, PyQt 4.8.4 32bit, and I could run "go()" many times without any crashes or warnings. However, there appears to be no "tournament" function. One advise, if I may say so: The chance of finding someone who would be willing to debugg your entire

[PyQt] Help tracking down intermittent segfault using QGraphicsItem

2013-01-04 Thread Lee Harr
I develop a free python turtle graphics application: http://pynguin.googlecode.com/ Right now I am trying to track down and fix an intermittent segfault involving a QGraphicsScene and QGraphicsItem Here is what I have... a QGraphicsItem subclass (item0) created with parent=None another QGraphic