Build failure: adding xdg-desktop-portal-gtk conflicts with GNOME's implementation

[freelock]

Steps To Reproduce

Steps to reproduce the behavior:

1. Set the following options:

  services.displayManager.sddm.enable = true;
  services.desktopManager.plasma6.enable = true;
  services.xserver.desktopManager.gnome.enable = true;

Build log

building the system configuration...
error: builder for '/nix/store/bywyrsnljzzln4csq9gk6585zhifcshy-user-units.drv' failed with exit code 1;
       last 1 log lines:
       > ln: failed to create symbolic link '/nix/store/jk674blqjdyjzbq3c2gwczapawxalz3m-user-units/xdg-desktop-portal-gtk.service': File exists
       For full logs, run 'nix log /nix/store/bywyrsnljzzln4csq9gk6585zhifcshy-user-units.drv'.
error: 1 dependencies of derivation '/nix/store/jyq18m9bv9y2gyjn57y6pcj513azmnsc-etc.drv' failed to build
error: 1 dependencies of derivation '/nix/store/1xwqgshgpjns6fh4f5v540nqkg55h5zv-nixos-system-valhalla-24.11.20240929.06cf0e1.drv' failed to build

Additional context

It looks like xdg-desktop-portal-gtk was added in c4c3b41

... I think Gnome modifies this package somehow, creating the conflict. This only breaks if you try to install both Gnome and Plasma6 simultaneously.

Notify maintainers

@K900

Metadata

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

❯ nix-shell -p nix-info --run "nix-info -m"
this path will be fetched (0.00 MiB download, 0.00 MiB unpacked):
  /nix/store/jvr4c9nb6xzw365px5gxh34sk88fqa7w-nix-info
copying path '/nix/store/jvr4c9nb6xzw365px5gxh34sk88fqa7w-nix-info' from 'https://cache.nixos.org'...
 - system: `"x86_64-linux"`
 - host os: `Linux 6.6.52, NixOS, 24.11 (Vicuna), 24.11.20240929.06cf0e1`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.18.8`
 - channels(root): `"nixos-23.11"`
 - nixpkgs: `/home/john/.nix-defexpr/channels/nixpkgs`

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Add a 👍 reaction to issues you find important.

[K900]

This is kind of normal, GNOME uses a different build of xdg-desktop-portal-gtk, so there's not much we can do here really. If you really want to have both, maybe run them in specializations.

[freelock]

I'm not really using Gnome very often, but rebuilding without it, I've lost a bunch of fonts in GTK apps... any suggestions?

[K900]

Install whatever fonts you need?

[JohnRTitor]

Causes issue if sway, hyprland, other Wayland compositors are enabled with GNOME since we are adding the portal there. #342646 (comment) CC @jtojnar

[jtojnar]

I think it should be fine to just enable all the portals in x-d-p-gtk unconditionally, now that the portal selection is configurable.

[Frontear]

I have been thinking of an alternative implementation:

1. Create a new options.xdg.portal.gtk.{enable, package}
2. Enable it in all relevant locations rather than directly adding

Benefits here would be overall deduplication, though in cases of GNOME/standalone compositor it WILL favor gnome. Honestly thats not something I can reasonably think of a fix for that doesnt include manually checking every single module possible.

If the implementation above suffices I will submit a new PR shortly. Just want community feedback.

[jtojnar]

I am not a fan of package options in general. And if we stop disabling the duplicate portals on GNOME, there should be no need for it anyway, the conflict will just disappear.

[Frontear]

The main reason I added the .package option was for GNOME/Cinnamon/Deepin, all of which override the default xdg-desktop-portal-gtk derivation

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/ln-failed-to-create-symbolic-link-nix-store-user-units-xdg-desktop-portal-gtk-service-file-exists/53876/4