Nixpkgs: Plank: Failed to get running applications

[davidak]

Issue description

I installed plank from unstable into a 18.03 system. It fails to get running applications.

[davidak@nixos:~]$ plank 

(plank:18322): Gtk-WARNING **: 15:37:12.758: Locale not supported by C library.
    Using the fallback 'C' locale.
[WARN 15:37:12.814197] [Environment:161] XDG_SESSION_CLASS not set in this environment!
[WARN 15:37:12.860595] [Preferences:192] '/run/current-system/sw/share/themes/Greybird/plank/dock.theme' is read-only!
[WARN 15:37:12.892718] Failed to get running applications: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.ayatana.bamf was not provided by any .service files
[WARN 15:37:12.898993] (Services/Matcher.c:296):plank_matcher_active_launchers: runtime check failed: (_tmp3_ != NULL)
[WARN 15:37:12.924205] Failed to register favorites: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.ayatana.bamf was not provided by any .service files
[WARN 15:37:12.994058] Creating surface took WAY TOO LONG (51ms), enabled downscaling for this cache!

On a different machine, also 18.03, i installed it using nix-env -i plank -f my-fork/ where i packaged it. There i don't have this problem.

Is there anything wrong with the method described below?

https://nixos.wiki/wiki/FAQ#How_can_I_install_a_package_from_unstable_while_remaining_on_the_stable_channel.3F

Steps to reproduce

1. add unstable channel using nix-channel --add https://nixos.org/channels/nixos-unstable nixos-unstable

2. include this into your configuration.nix

{ config, pkgs, ... }:

let
  unstable = import <nixos-unstable> {};
in
{
  environment.systemPackages = with pkgs; [
    unstable.plank
  ];
}

1. nixos-rebuild switch --upgrade
2. [davidak@nixos:~]$ plank

Technical details

• system: "x86_64-linux"
• host os: Linux 4.14.52, NixOS, 18.03.132803.2f06e04b74e (Impala)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.0.4
• channels(root): "nixos-18.03.132803.2f06e04b74e, nixos-hardware, nixos-unstable-18.09pre143771.a8c71037e04"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs

[worldofpeace]

I think this is related to #38991

[worldofpeace]

@davidak This needs bamf in services.dbus.packages postulated by @jtojnar
If you could test that for me It would help me in mutually packaging elementary.

[worldofpeace]

So I've packaged gala and when it's running plank will start yet it still cannot get the current running applications. But I haven't tested it with what was postulated.

[jtojnar]

I am looking into this. One problem is incorrectly seded location of units, though fixing it does not seem to be enough either. I also opened an upstream issue about the hardcoded path https://bugs.launchpad.net/bamf/+bug/1780557

[worldofpeace]

So i added bamf and with gala running plank just works.

[worldofpeace]

[jtojnar]

How did you add bamf? I can run it manually and have plank work, but for some reason systemd does not see my user service even with the fixed package: https://github.com/jtojnar/nixpkgs/tree/bamf

[worldofpeace]

I added it the way you said and I rebooted.

[jtojnar]

Hmm, perhaps the restart is needed. I can run it fine in VM. Feel free to cherry-pick the commits to your branch.

[davidak]

I reproduced the issue on 18.09pre145524.2a8a5533d18 (Jellyfish).

It is fixed with the changes from @jtojnar and services.bamf.enable = true;.

Thank you very much!

(Would it be possible to enable it by default when plank is installed?)

[jtojnar]

Nix unfortunately does not support requiring NixOS options (remember, Nix also targets platforms other than NixOS).