workstation-ostree-config/fedora-xfce.json

{
    "ref": "fedora/rawhide/${basearch}/xfce",
    "repos": ["fedora-rawhide"],
    "automatic_version_prefix": "29",
    "mutate-os-release": "29",

    "include": "xfce-desktop-pkgs.json",

    "packages": [
        "xdg-desktop-portal-gtk"
    ]
}