Has anyone had this problem - Kwin crashes ( at least I think it's that - all the
decorations vanish ) when I start Chrome

Plasma 5.5.3
Nvidia
opensuse

M

backtrace or it didn't happen :-P

"developer information" in DrKonqi => report to bugs.kde.org

I am having the same problem ever since the upgrade to 5. It is not a full crash - the bug report screen does not come up. Window decorations disappear, windows cannot be resized or moved and anything that should appear on top of something else (e.g. menus, right-click context menus etc) does not work. Keyboard entries work - in some windows.

Running "kwin" through krunner fixes it. I have two machines with the same problem, both on a dual monitor setup. On one of the machines, restarting KWin brings up normal window decorations but the taskbar is more transparent than before. On the other, the restart brings some other decorations (again with a more transparent task bar).

For me, this usually occurs when opening a new window, though I do not use chrome, so I do not think it is the culprit. I haven't pinpointed any specific window which causes this.

I think it has something to do with the decorations are old (KDE4) and do not work properly. With some decorations I cannot resize the windows. I work with the "Breeze" decoration (which works fine) and see whether that changes anything.

If there is a way to log / record this to help fix it (since Dr. Konqi does not come up), let me know and I will try it out.

"Old" decorations (in terms of binary plugins) aren't supported by KWin/5 (though aurorae themes will work, there're some QtQuick related bugs, though)

If you don't get a drkonqi dialog you either
a) don't have drkonqi installed (in that case you may or may not get a core dump, depending on your system config - that's not KDE specific)
b) run into a bug where KWin fails to restart due to a stopped instance, held by drkonqi

=> ensure to have drkonqi installed (it's a separate package in KDE5) and if you still don't get a dialog, check the process list for a stopped (status "T") kwin_x11 instance which you can gdb into.

luebking wrote:"Old" decorations (in terms of binary plugins) aren't supported by KWin/5 (though aurorae themes will work, there're some QtQuick related bugs, though)

If you don't get a drkonqi dialog you either
a) don't have drkonqi installed (in that case you may or may not get a core dump, depending on your system config - that's not KDE specific)
b) run into a bug where KWin fails to restart due to a stopped instance, held by drkonqi

=> ensure to have drkonqi installed (it's a separate package in KDE5) and if you still don't get a dialog, check the process list for a stopped (status "T") kwin_x11 instance which you can gdb into.

Hi,

Thanks for the reply. I definitely have drkonqi installed, the package is there and I have used it to report crashes, so it's the second case.

I guessed it was an aurorae theme problem. I have been using the default breeze decorations the whole week and the problem has not reappeared, not once, whereas with the other decorations I used to encounter it at least 3-4 times a day.

Also, as you say, when this happens a stopped kwin_x11 instance is present.

Do you want me to try to reproduce the bug? I am not sure how to do it with gdb, so I will need some help. However, if you guys are planning on dropping support for aurorae decorations at some point, is there any point in investigating? If so, I will do what I can to help.

DrKonqi & Stopped kwin_x11 will be fixed (hopefully in 5.6 - it might be worth to recause the aurorae bug, though we've several "typical" aurorae related crashes in QtQuick (you'll likely see some QV4::ExecutionEngine::newStringObject in the backtrace)

luebking wrote:DrKonqi & Stopped kwin_x11 will be fixed (hopefully in 5.6 - it might be worth to recause the aurorae bug, though we've several "typical" aurorae related crashes in QtQuick (you'll likely see some QV4::ExecutionEngine::newStringObject in the backtrace)

That's great! Can you please tell me how to get a backtrace using gdb when the bug happens so that I can try to reproduce the bug?

https://community.kde.org/KWin/Debugging

Notice that "pidof kwin_x11" won't work since there're several kwin_x11 processes. You must explicitly pass the PID of the stopped one.

What happens if users that have windows decorations from when we had KDE4
if we move to Plasma 5. Are they going to have crashes - do we need to wait for 5.6 ?

Ta

M

ideally, you should not have such deco, because it would miss dependencies (unresolved libraries), but even then, it's just ignored and you'll pick a failsafe.
nb, that this affects decoration plugins - not eg. aurorae themes.

luebking wrote:ideally, you should not have such deco, because it would miss dependencies (unresolved libraries), but even then, it's just ignored and you'll pick a failsafe.
nb, that this affects decoration plugins - not eg. aurorae themes.

I am sorry, I am confused. Are aurorae themes compatible with KWin5 or not? Apart from the OP's crash, I have a problem with aurorae themes (at least, I think they are aurorae). Setting border size to "tiny" does not allow any window resizing from a window's borders (the cursor never changes to the corresponding "resize" cursor), yet a "normal" border size seems to work. For example, the "olympic" window decoration, but this seems to be a recurring problem with other aurorae themes too. Setting the window decorations to "Breeze" does seem to have this problem, tiny border sizes work fine. Does it have to do with the decoration itself?

If the aurorae decorations do not work consistently, wouldn't it better if the user was not allowed to choose them from the relevant systemsettings module? I wouldn't mind fewer choices, if I knew that these choices would work consistently.

Yes - they're "just" themes.
But there're several (or only one?) problems with the aurorae decoration pugin in KDE5 which seem to be related to QtQuick.

The tiny border is reproducible. I frankly don't know too much about the theme, but it seems tiny borders are just as unsupported as no side borders (or borders at all) - or maybe this needs to be announced by the theme, but this is a bug in the aurorae decoration and NOT an incompatibility w/ KWin 5

Afaics, your choices minus aurorae are "breeze".
Plastik doesn't share the tiny border issue (so it does indeed seem a theme limitation) but will share the QtQuick related issued (ie. crashes)

I am also really confused. What will happen to my users if we rolled out
something like Leap 42.1 with plasma 5 since nearly every user I have
has downloaded a different decoration for openSUSE 13.2 and KDE 4.14

Ta

M

Themes are not imcompatible but the aurorae decoration is pretty crash prone, see the three red bugs in https://bugs.kde.org/buglist.cgi?compon ... lution=---

I would agree with the earlier post that you shouldn't be able to install
themes that crash the desktop, it puts Plasma in a really bad light. I use
Plasma 5 at home since I don't mind Plastik and that seems OK but as
soon as we put it out at school the students will install anything and everything
possible and I will be inundated with frozen desktops .

M