MIME Default applications clobbered by kde-mimeapps

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1

I am trying to set my default pdf viewer to sioyek and I’m encountering an annoying issue. I have looked at the other relevant threads on here but no-one seems to have directly addressed my issue.

I use home-manager to set it as the default like so:

    /*
    Default Apps
    */
    xdg.mimeApps = {
      enable = true;
      associations.added = {
        "application/pdf" = ["sioyek.desktop"];
      };
      defaultApplications = {
        "application/pdf" = ["sioyek.desktop"];
      };
    };

But when I run:

 XDG_UTILS_DEBUG_LEVEL=2 xdg-mime query default application/pdf

I get:

Checking /home/<user>/.config/mimeapps.list
Checking /home/<user>/.local/share/applications/mimeapps.list
Checking /run/current-system/sw/share/applications/kde-mimeapps.list
okularApplication_pdf.desktop

The first two files are correctly configured by home-manager to use sioyek. But the final one overrides them with the KDE default mime type packaged with plasma (see plasma-desktop/kde-mimeapps.list at f8085d49c438d771b1218cc8a4742c80752f398a · KDE/plasma-desktop · GitHub).

How do I resolve this? It seems some applications go with ~/.config/mimeapps.list which will correctly open sioyek, but others use xdg-open which will go with okular.