Modrinth doesn't launch on unstable channel

[JonasFranke]

Describe the bug

The modrinth-app package does not launch when being on unstable channel

Steps To Reproduce

Steps to reproduce the behavior:

1. add modrinth-app (or modrinth-app-unwrapped) to nixpkgs (unstable)
2. run nixos-rebuild
3. try to start modrinth

Expected behavior

Modrinth starts as expected

Screenshots

Additional context

Metadata

 - system: `"x86_64-linux"`
 - host os: `Linux 6.6.63, NixOS, 24.05 (Uakari), 24.05.6818.6f6076c37180`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.18.8`
 - channels(root): `"home-manager-24.05.tar.gz, nixos-24.05, nixos-unstable"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

Notify maintainers

@getchoo

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[getchoo]

Do you have a NVIDIA card? There are a lot of known bugs with webkitgtk and the drivers currently, including just segfaulting on launch

[JonasFranke]

Do you have a NVIDIA card? There are a lot of known bugs with webkitgtk and the drivers currently, including just segfaulting on launch

yep, is there a workaround? By e.g. using the integrated graphics?

[getchoo]

Integrated graphics is one solution (as Mesa shouldn't be affected by this), but you may also be able to set WEBKIT_DISABLE_DMABUF_RENDERER=1 and/or WEBKIT_DISABLE_COMPOSITING_MODE=1 to fix it. See tauri-apps/tauri#9394 and tauri-apps/tauri#9304 as well

[youwen5]

$ ModrinthApp
fish: Job 1, 'ModrinthApp' terminated by signal SIGSEGV (Address boundary error)

I get the above whenever I try to launch Modrinth. None of the environment variables seem to do anything. Any idea if this could be nixpkgs related, or should I open an issue in Modrinth?

[getchoo]

Any idea if this could be nixpkgs related, or should I open an issue in Modrinth?

This is more likely to be a webkitgtk & NVIDIA issue rather than either us or Modrinth. It happens across all Tauri apps

[youwen5]

Any idea if this could be nixpkgs related, or should I open an issue in Modrinth?

This is more likely to be a webkitgtk & NVIDIA issue rather than either us or Modrinth. It happens across all Tauri apps

Weird, cause I do Tauri development on my local machine and I'm able to compile and run using both a Nix derivation and Cargo directly. I will investigate webkitgtk further, I guess.

[getchoo]

You'll probably want to see the upstream (Tauri) issues above. They in turn link to most of the webkitgtk bug reports

[CrazyWolf13]

Hi
I can confirm this behaviour, I get this error:

2025-01-10T21:56:15.449730028+01:00  INFO theseus_gui: Initialized tracing subscriber. Loading Modrinth App!
2025-01-10T21:56:15.453688323+01:00  INFO theseus_gui: Initializing app...

Issue happens since I switched from default nixos to the proprietary nvidia drivers.

I've set:

	environment.sessionVariables = {
		"WEBKIT_DISABLE_DMABUF_RENDERER" = "1";
		"WEBKIT_DISABLE_COMPOSITING_MODE" = "1";
	};

And I'm also on wayland, though this did not fix anything, anything else I coud try?

The other things mentioned in the linked tauri issues either don't seem to apply to me or also don't fix the issue.

EDIT:
I finally found a fix on an older reddit thread:

adding GDK_BACKEND=x11 makes it work again.
(NixOS Wayland Gnome)

[CrazyWolf13]

@getchoo
Is there any good way on adding this to my nixos config? Or even directly to the packagebuild?

Applying GDK_Backend=x11 globally to my whole system is not really something that seems like a good idea to me.

[getchoo]

Not tested, but I believe something like this should work

{ pkgs, ... }:

{
  environment.systemPackages = [
    (pkgs.modrinth-app.overrideAttrs (oldAttrs: {
      buildCommand =
        ''
          gappsWrapperArgs+=(
             --set GDK_BACKEND x11
             --set OTHER_ENVVAR VALUE
          )
        ''
        + oldAttrs.buildCommand;
    }))
  ];
}

(with OTHER_ENVVAR and VALUE being placeholders for anything else you may want to set)

[CrazyWolf13]

Thank you soooo much!
This snippet worked for me:

	environment.systemPackages =  
	with pkgs; [
		(modrinth-app.overrideAttrs (oldAttrs: {
			buildCommand = 
				''
					gappsWrapperArgs+=(
						--set GDK_BACKEND x11
						--set WEBKIT_DISABLE_DMABUF_RENDERER 1
					)
				''
				+ oldAttrs.buildCommand;
		}))

	];