Plasmashell dumps core when disconnecting a third (hdmi) display

System becomes unresponsive (hard restart required) after disconnecting the third display via hdmi switch - which I do quite often as the third display doubles as a TV.
Coredump created on this occasion.
Remaining two displays (connected via DVI) normally should refresh and show the reconfigured desktop - but they remain black - and no keyboard input can bring the system back.

Linux/KDE Plasma: Manjaro 21.1.0
KDE Plasma Version: 5.22.4
KDE Frameworks Version: 5.85.0
Qt Version: 5.12.2

I reported this with kde bugs, only to get it closed as a duplicate of another two year old bug - which itself was closed as ‘resolved upstream’ - apparently in Qt 6 (see 414805 – Crash in QScreen::handle() after QXcbIntegration::createPlatformOpenGLContext())

It looks like in this case Qt is upstream of KDE, and KDE is upstream of Manjaro. Right?

  • What is the process to get this fixed in Manjaro?

Sorry for the n00b questions, but I am genuinely interested in the process - if someone can shed some light please.

Please read this:


Please read this:

Especially the What’s this upstream/downstream business as the answer is: it needs to be fixed in KDE and if it was fixed recently, the next update will incorporate the change.

In that case, read the rest of the N00b guide too! :grin: (at least the sections you’re not aware of)


I’ve marked this answer as the solution to your question as it is by far the best answer you’ll get.

However, if you disagree with my choice, please feel free to take any other answer as the solution to your question or even remove the solution altogether: You are in control! (If you disagree with my choice, just send me a personal message and explain why I shouldn’t have done this or :heart: or :+1: if you agree)

P.S. In the future, please don’t forget to come back to your question after your issue has been solved and click the 3 dots below the answer to mark a solution like this below the answer that helped you most:
so that the next person that has the exact same problem you just had will benefit from your post as well as your question will now be in the “solved” status.

Well then Fabby, it was a nice read. Thanks for taking your time and writing that up.
I am more informed now then I was an hour ago.

Going to enable sysrq now and test it out for next time - as I am at the mercy of KDE for the time being.

Also, perusing the tutorial section of the forum (now that I see it is quite nicely populated).

Cheers :wave:

1 Like

How to thank people here on the forum

  1. The best 'Thank you" you can give someone in a thread you started, is to press the Solution button. (Only if that answer actually solved your problem!!!)
  2. The 2nd best 'Thank you" is by pressing the :heart: emoji below their post.
  3. The 3rd Best 'Thank you" is by pressing the black emoji and giving them :beer: :+1:
  4. And last, but not least, it’s writing 'Thank you".

Why??? Oh, why, you ask? :grin:

That’s because the forum software tallies the solutions and :heart: and gives these people bragging rights to the other geeks and nerds here on the forum, and eventually unlocks more privileges for them…


This topic was automatically closed 2 days after the last reply. New replies are no longer allowed.