Freezing in Style

One of the the less apparent omissions in Plasma’s Wayland session compared to X was the lack of a prompt for terminating an unresponsive app. Of course, you should never see one because any decent app will just crash and quit rather than get stuck. Nevertheless, over the course of three evenings I spent way too much time making the “KWin Killer Helper” work on Wayland and while at it revamped its user interface entirely.

This is a companion discussion topic for the original entry at

I still have CTL+ALT+ESC set to give me a xkill skull and crossbones. Every time I get one of the message boxes, it just seems to do nothing. I hope you can make this work the way it should.

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Nice blog post! Did you consider using the “application crashed” sad face icon as the overlayed icon instead of the more generic orange exclamation mark?


Spurious text to make 20 characters.

I did not because the icon is black with no backdrop it will be hard to see ontop of an icon, hence we have those “emblem” style icons (like the “is symlink” or “access denied”) with a solid colored background.

Also, I still wanted to convey some sort of danger since terminating a process will lose all unsaved data.

On X11

My issue with this is that most of the time, if an app freezes, getting a box that offers a wait or shutdown is a crapshoot. I get the box maybe 25% of the time and even then, it is after trying to shutdown the app from the icon on the panel. Then another 25% of the time will the box actually work. I end up wasting a couple of minutes figuring out that I have to kill it manually.

Xkill never fails and it is instantaneous. It’s a whole lot easier than tracking the application down in htop and killing it there. I remember when it was installed by default. Now, you have to install it manually.

On Wayland, if you can get this to work “properly,” it will be awesome. If not, is it possible to create something like xkill for wayland?

There is a kill window shortcut in Wayland.

It can even kill plasmashell :rofl:


I literally said in the blog post that on X we only do the ping when closing the app.

I read that. I still don’t know what it means.

It means on X we only check if the application is responsive when trying to close it. On Wayland we can safely do that more often and provide the opportunity to end a frozen program more quickly.


Excellent. I will remember to use it when I switch to Wayland. I just checked it on my old laptop and it works just like xkill.

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Great read. :ok_hand:

Not quite related, but I appreciate the effort in explaining what the Wayland protocols are for.