bug: Pipewire screencasting broken on non-NixOS (Fedora)

[YTG1234]

Are you following the right branch?

• My Nixpkgs and Home Manager versions are in sync

Is there an existing issue for this?

• I have searched the existing issues

Issue description

Using Fedora 41, with KDE Plasma 6.

In OBS (system-installed), the Pipewire screencast option never even opens a dialogue. Checking the log of plasma-xdg-desktop-portal-kde.service reveals

xdp-kde-screencast: zkde_screencast_unstable_v1 does not seem to be available

The xdg.portal section of my configuration:

      portal = {
        enable = false;
        config.kde = {
          default = [ "kde" ];
          "org.freedesktop.impl.portal.Settings" = [ "kde" ];
          "org.freedesktop.impl.portal.FileChooser" = [ "kde" ];
          "org.freedesktop.impl.portal.Secret" = [ "kwallet" ];
        };
        extraPortals = with pkgs; [
          kdePackages.xdg-desktop-portal-kde
          kdePackages.kwallet
        ];
        xdgOpenUsePortal = true;
      };

enable is set to false — because the issue was also occuring with it set to on, I disabled it to test, but it doesn't have any effect.

Likewise, I don't have pipewire enabled in my configuration, as I use the system-installed version.

Uninstalling home-manager fixes the problem, so it (or rather my configuration) is clearly at fault.

Maintainer CC

No response

System information

- system: `"aarch64-linux"`
 - host os: `Linux 6.13.5-400.asahi.fc41.aarch64+16k, Fedora Linux Asahi Remix, 41 (KDE Plasma), nobuild`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Lix, like Nix) 2.92.0
System type: aarch64-linux
Additional system types:
Features: gc, signed-caches
System configuration file: /etc/nix/nix.conf
User configuration files: /home/ytg/.config/nix/nix.conf:/home/ytg/.config/kdedefaults/nix/nix.conf:/etc/xdg/nix/nix.conf:/etc/xdg/nix/nix.conf
Store directory: /nix/store
State directory: /nix/var/nix
Data directory: /nix/store/jpnhz8l3lxdjl7p7zlfyrxif1qa5f28d-lix-2.92.0/share`
 - channels(root): `""`
 - nixpkgs: `/nix/store/sznkl4iwqvxprlg05fx24xx8bd8j7y6l-source`

[YTG1234]

Is there any sort of temporary solution, even some parameters to set for the portal / Pipewire services, that would sort this for the time being? Of course in the long term I'm looking for something that can be done in my home-manager configuration, but for now, even ideas for something very hacky would be appreciated.

[YTG1234]

The plot thickens: I tested it in an x86_64 VM, and everything was working. So this is either a problem on aarch64 or (more likely) on Asahi Linux specifically.