Arch Linux

rohanprabhu

Member

Registered: 2011-08-23

Posts: 16

KWin Alt+Tab not working after plasma update (5.7)

So, I recently did a `pacman -Syu` and after that, I am not able to Alt+Tab anymore. However, Meta+Tab for activity cycling works, but I think Plasma handles that and not kwin. I am currently only Plasma 5.7 and running KWin for X11.

 ~ ツ ps aux | grep kwin; kwin_x11 --version
rohan     1445  0.0  0.4 3087204 70452 ?       Sl   Jul11   0:22 /usr/bin/kwin_x11 --crashes 1
rohan    16533  0.0  0.0  10776  2152 pts/2    S+   15:27   0:00 grep --color=auto kwin
kwin 5.7.0
 ~ ツ 

Any help is greatly appreciated.

alive4ever

Member

Registered: 2016-07-10

Posts: 65

Re: KWin Alt+Tab not working after plasma update (5.7)

I'm also on plasma 5.7 with no alt+tab issue

$ pgrep -a kwin
1221 kwin_x11 -session 10c699d9d9000146744711400000305340003_1467447200_21519

My output of running kwin_x11 doesn't have --crashes 1. So I think you have kwin crash. Have you looked at system logs for any clue?

FYI, Alt+Tab is handled by 'window manager' such as kwin or openbox. For diagnostic purpose, you may also install openbox and select KDE/OpenBox from the login greeter to see if alt+tab works on Openbox window manager.

You should also check 'Global Keyboard Shortcuts' on KCM. Look at kwin under KDE component. Make sure that kwin 'Walk through windows' global shortcut is defined as Alt+Tab.

Last edited by alive4ever (2016-07-12 12:30:01)

rohanprabhu

Member

Registered: 2011-08-23

Posts: 16

Re: KWin Alt+Tab not working after plasma update (5.7)

So, this is really weird. On a whim, I basically went ahead and did a `kwin_x11` from my terminal and saw this output:

(master ±) nodeauthority ツ kwin_x11
kwin: unable to claim manager selection, another wm running? (try using --replace)
Application::crashHandler() called with signal 11; recent crashes: 1
KCrash: Application 'kwin_x11' crashing...
[2]    8450 segmentation fault (core dumped)  kwin_x11
(master ±) nodeauthority ✖ QPainter::begin: Paint device returned engine == 0, type: 3
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::setWindow: Painter not active
QPainter::setClipRect: Painter not active

... lot many more error lines

However, my Alt+Tab sequence now works. Rebooting my machine makes Alt+Tab stop working again. I guess I should look into logs as to what exactly is happening at startup time.