Reasoning:
I tried switching from GNOME to KDE because I read about how configurable it is,
(initially GDDM Wayland + Plasma 6 Wayland), but found that it didn’t work.
I then tried all other possible combinations of GDDM X11/Wayland and Plasma 5/6 X11/Wayland.
None of the combinations worked properly, either booting to the terminal, or booting to GDDM
and failing to launch Plasma.
Then, trying to gather context for the issue report, I tried using LightDM (which didn’t work
either). Then I tried using GDM (GNOME Display Manager) with Plasma 6 Wayland, which was more
likely to work given I had previously used GNOME without any issues, and it worked properly!
Given this, I know believe the issue is to do with GDDM rather than Plasma.
Details:
GDDM X11 and LightDM didn’t launch, instead the terminal did.
GDDM Wayland was stuck trying to launch Plasma Wayland.
GDDM Wayland tryed to launch Plasma X11, but then just returned to the login screen.
GDM worked as expected.
Ending:
For now I’m fine using a mismatched display manager, but it would be nice if this was fixed.
I think that this issue is device specific (Dell G16 (7630)), as I haven’t found anyone else
reporting an issue like this. This also seems to be (at least partially) specific to NixOS,
as I had previously used Linux Mint (LightDM) without issues.
System details:
I am on NixOS Unstable, DE says system is ‘NixOS 24.11 (Vicuna)’.
Laptop is Dell G16 7630.
Plasma Info Center says (when using Plasma 6 with GDM):
Operating System: NixOS 24.11
KDE Plasma Version: 6.1.3
KDE Frameworks Version: 6.4.0
Qt Version: 6.7.2
Kernel Version: 6.6.43 (64-bit)
Graphics Platform: Wayland
Processors: 32 × 13th Gen Intel® Core™ i9-13900HX
Memory: 15.3 GiB of RAM
Graphics Processor: Mesa Intel® Graphics
Manufacturer: Dell Inc.
Product Name: Dell G16 7630