Help with debugging a bug in Konqueror

[Stefano Crocco]

On lunedì 13 luglio 2026 08:49:46 Ora legale dell’Europa centrale you wrote:
> On Mon, 2026-07-13 at 08:41 +0200, Stefano Crocco wrote:
> > Hello to everyone,
> > for the last few weeks, I've randomly encountered what I assume is a
> > bug in
> > Konqueror: I'd like to fix it, because it's rather annoying, but I
> > don't know
> > how to debug it to find its cause.
> > 
> > The issue is that sometimes Konqueror completely freezes: none of its
> > windows
> > respond to mouse or keyboard. The only way to go on is to kill it.
> > It's not a
> > frequent issue: it usually happens once a day or so. Once it has
> > happened,
> > however, it's likely to happen again in a short time.
> > 
> > I attach a backtrace by attaching gdb to the Konqueror instance once
> > the
> > freeze happens. As you can see, it contains almost nothing from
> > Konqueror
> > itself: just two calls near the bottom, the last of which is a call
> > to
> > QApplication::exec(). All other function calls are either inside KDE
> > Frameworks or Qt: I'd almost think this is not a problem with
> > Konqueror if it
> > were not for the fact that I'm only experiencing the issue with
> > Konqueror.
> 
> Are you sure freeze happens in that thread?
> 
> The stacktrace is from the rendering thread. Does Konqueror window get
> "grayed out" by KWin when it freezes? If it doesn't I'd think the
> freeze happens in another thread.

Thanks for the answer. No, the Konqueror  window doesn't look grayed out: it 
looks completely normal to the point that often I don't realize it has frozen 
until I try to interact with: only at that point I notice that all parts of 
the UI don't respond in any way yo mouse or keyboard. If I minimize the 
window, then restore it, its contents aren't drawn so that it shows the 
contents of the previously active window.

> > Given the randomness of the freezes and the fact that the backtrace
> > contains
> > almost no Konqueror-specific calls, I really have no ideas on how to
> > proceed to
> > debug the issue, and I really don't even know what to search on the
> > web. Do
> > you have any advice?
> > 
> > Thanks in advance
> > 
> > Stefano

I attach a new backtrace with all threads (compressed because of size). I 
still can't see anything related to Konqueror. The only thing I can notice is 
a mention of QDBus in thread 67, but I still don't know what information to 
get from it. Any other ideas?

Thanks

Stefano
-------------- next part --------------
A non-text attachment was scrubbed...
Name: backtrace_all_threads.zip
Type: application/zip
Size: 5788 bytes
Desc: not available
URL: <http://mail.kde.org/pipermail/kde-devel/attachments/20260713/b631d5bb/attachment-0001.zip>