Nixpkgs: Conflicting definitions for programs.ssh.askPassword in plasma5 and seahorse

[romildo]

Describe the bug

When plasma5 and gnome3 are enabled on my configuration.nix I get the following error:

# nixos-rebuild boot 2>&1 | tee /var/log/nixos-rebuild.log
building Nix...
building the system configuration...
trace: warning: mlocate does not support searching as user other than root
error: The option `programs.ssh.askPassword' has conflicting definitions, in `/nix/var/nix/profiles/per-user/root/channels/nixos/nixos/modules/services/x11/desktop-managers/plasma5.nix' and `/nix/var/nix/profiles/per-user/root/channels/nixos/nixos/modules/programs/seahorse.nix'.
(use '--show-trace' to show detailed location information)

Metadata

• system: "x86_64-linux"
• host os: Linux 5.4.3, NixOS, 20.03pre205624.8636580d6f4 (Markhor)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.1
• channels(root): "nixos-20.03pre205710.352f030b715"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module: services/x11/desktop-managers/plasma5.nix programs/seahorse.nix

[hedning]

Right, I thought mkDefault would take care of that, but apparently not. Is the only way to fix things like these to hardcode a specific priority @worldofpeace?

[worldofpeace]

Right, I thought mkDefault would take care of that, but apparently not. Is the only way to fix things like these to hardcode a specific priority @worldofpeace?

In the instance of multiple declarations of programs.ssh.askPassword, I think it should just null itself out. There's no value that can be appropriately determined.

Edit: when I mean should, that's how it should behave when fixed.

[knedlsepp]

Experienced this evaluation error when bumping to 20.03. Not yet knowing what this actually implies, I'm currently working around this by setting:

{ config, pkgs, ... }: {
  services.xserver.desktopManager.plasma5.enable = true;
  services.xserver.desktopManager.gnome3.enable = true;
  programs.ssh.askPassword = pkgs.lib.mkForce "${pkgs.plasma5.ksshaskpass.out}/bin/ksshaskpass";
}

[worldofpeace]

@knedlsepp This means, default, you can't evaluate using both gnome3 and plasma5?

[knedlsepp]

@knedlsepp This means, default, you can't evaluate using both gnome3 and plasma5?

That's correct. I haven't tried the actual minimal example, but disabling either plasma5 or gnome3 would also make it evaluate, so I'm guessing it's the same issue as the OP describes.

[hedning]

So we could add different priorities to the gnome/plasma mkDefault, but that's pretty hacky. Ideally we'd have a better way to do per desktop config. That's doable by pushing things into shellInit and matching on XDG_DESKTOP_SESSION. That's hardly super pretty either, but it would solve the problem.

[jnoortheen]

I bumped into the same issue.

Experienced this evaluation error when bumping to 20.03. Not yet knowing what this actually implies, I'm currently working around this by setting:

{ config, pkgs, ... }: {
  services.xserver.desktopManager.plasma5.enable = true;
  services.xserver.desktopManager.gnome3.enable = true;
  programs.ssh.askPassword = pkgs.lib.mkForce "${pkgs.plasma5.ksshaskpass.out}/bin/ksshaskpass";
}

this fixes the issue just after removing the gnome3 line.