Describe the bug
I've update to NixOS 20.09
in KDE config, some configuration tabs are broken displaying the message
undefined symbol: _ZN3KIO32UntrustedProgramHandlerInterface16staticMetaObjectE

i've searched (rg UntrustedProgramHandlerInterface16staticMetaObjectE /nix ~/.cache/ ~/.config/ ~/.local/) this string but found nothing

To Reproduce
Steps to reproduce the behavior:

1. have a working configuration with NixOS 20.03
2. upgrade to NixOS 20.09
3. it's broken

Expected behavior
KDE config should be available and working

Screenshots

Notify maintainers

Metadata
Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

• system: "x86_64-linux"
• host os: Linux 5.4.72, NixOS, 20.09.1500.edb26126d98 (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.7
• channels(pinage404): "home-manager-20.03, nixos-20.03.3158.7c2a362b58a, nixos-unstable-21.03pre248170.007126eef72"
• channels(root): "nixos-20.09.1500.edb26126d98"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module:

i don't know there is no maintainers in https://github.com/NixOS/nixpkgs/blob/master/pkgs/desktops/plasma-5/systemsettings.nix