Sddm[]: Failed to read display number from pipe

English Install/Boot/Login
1

Besides other symptoms that have existed for a long time (about sleep), this one is new after recent updates.

  1. When PC is boot from cold, it always ends up in a black screen (before login). Keyboards light’s up and you can do ‘ctrl+alt+del’ instantly but ‘ctrl+alt+F1’ still sends you to black screen.
  2. If using ‘ctrl+alt+del’ after boot failure, most of the times next boot will be fine.
  3. Upon getting into normal boot and check log with sudo journalctl -b -1 -p err, there’s always this error: “sddm: Failed to read display number from pipe”.
  4. Forum search shows someone did sudo sddm --default-config >> /etc/sddm.confsuggeted by ChatGPT but some say it didn’t make sense.
    Any thoughts before I try ChatGPT’s trick too?
2

What video card??? There have been problems with new kernels an Nvidia drivers

3

Nvidia for sure. But my error log didn’t show nvidia is having issue. I did have problem with nvidia at first, then I uninstalled and completely reinstalled nvidia. Now it seemes to me unrelated to nvidia anymore. That said, I have had problem to let my PC go to sleep for the past 2 years or so and I have stopped caring about that issue, which I think is related to nvidia.

4

@moshpuke

I doubt this is an answer to the question.