Broken KDE Plasma install

Help
1

TLDR

I tried installing NixOS with the KDE Plasma Desktop, but it results in a broken install with no applications (though some programs still exist e.g. Dolphin), and on login it shows an error “Could not enter folder tags:/.”. I then tried installing again but when prompted to choose the desktop environment I chose Gnome instead of Plasma and it works perfectly.

Install NixOS with Plasma Desktop

The way I installed it is I flashed the NixOS live installer (I tried with both the Gnome and Plasma versions of the installer) to a 16GB USB drive using EtchDroid (which is a port of Balena Etcher for android). Then I booted the live OS on my PC and went through with the installation steps, choosing “Plasma” as the desktop environment.

Not sure if this is the cause of the issue or if it is even relevant, but when choosing the disk to install on, I manually created the partitions. I previously had installed Fedora 41, but I deleted all of it and only left the home partition.

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I also tried using separate partitions for /boot (512 MiB) and /boot/efi (500 MiB) but got the same results.

Then I let it install the OS and rebooted. It boots to the Plasma SDDM and everything looks normal, but when I log in to my user I see this:

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I tried opening the terminal but there are no applications. clicking the system tray lets me configure WiFi and everything else that is present in the tray.
Trying to open the Desktop files shows this:
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From this window I can click “Choose other...” to show a file picker, and from there I can open Dolphin. I saw that everything was there in the my home directory, but on root there were clearly a lot of things missing. E.g. /usr only had one file /usr/bin/env.

2

Your issue is probably that you used the existing user home directory from the Fedora install without changing the username or moving the existing user home directory. There are likely stale files from the Fedora install in your home directory getting in the way of the NixOS system.

If your partitions are the way you intend them to be I would suggest essentially reinstalling overtop the existing install and moving the old user home directory out of the way first. You would boot the NixOS installer, mount the partitions where they go, move the old user home (now at /mnt/home/username) to a different directory name, and then continuing with reinstalling NixOS from that point with the NixOS configuration files that were generated previously. This would leave you with old user files still accessible to be copied back into the new users home directory.

I’m assuming the Fedora install had Plasma desktop so when you tried Gnome on NixOS the Gnome desktop didn’t care about the old Plasma files left there by the Fedora install and that’s why Gnome worked.

3

I did have Fedora with Plasma, so that’s probably it. Also later on I notices that on the Gnome install the home partition wasn’t actually mounted. I’m going to delete the home partition and create an empty one since I have a backup with all the files I wanted to keep, and copy the backup to the new home.

Thanks for your help :slight_smile: