Gnome3 and Pantheon in the same system does not build

[romildo]

Issue description

I want to have gnome3 and pantheon desktop managers in the same NixOS system, so that the user can choose the desired one at login time. So I have on configuration.nix:

  services.xserver.desktopManager.pantheon.enable = true;
  services.xserver.desktopManager.gnome3.enable = true;

But nixos-rebuild gives the following error:

error: The unique option `networking.networkmanager.basePackages.modemmanager' is defined multiple times, in:
 - /nix/var/nix/profiles/per-user/root/channels/nixos/nixos/modules/services/x11/desktop-managers/pantheon.nix
 - /nix/var/nix/profiles/per-user/root/channels/nixos/nixos/modules/services/x11/desktop-managers/gnome3.nix.
(use '--show-trace' to show detailed location information)

cc @worldofpeace

Technical details

• system: "x86_64-linux"
• host os: Linux 5.1.16, NixOS, 19.09pre184855.beff2f8d75e (Loris)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.2.2
• channels(root): "nixos-19.09pre184855.beff2f8d75e"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

[worldofpeace]

Currently there's a bit of work to be done so that both these session can exist on a system
without conflicting with each other and making a session unusable.

At first something like

diff --git a/nixos/modules/services/x11/desktop-managers/gnome3.nix b/nixos/modules/services/x11/desktop-managers/gnome3.nix
index ef6820d3326..9e8482432b4 100644
--- a/nixos/modules/services/x11/desktop-managers/gnome3.nix
+++ b/nixos/modules/services/x11/desktop-managers/gnome3.nix
@@ -206,7 +206,7 @@ in {
       isSystem = true;
     };
 
-    environment.variables.GNOME_SESSION_DEBUG = optionalString cfg.debug "1";
+    environment.variables.GNOME_SESSION_DEBUG = mkIf cfg.debug "1";
 
     # Override default mimeapps
     environment.variables.XDG_DATA_DIRS = [ "${mimeAppsList}/share" ];
@@ -228,7 +228,7 @@ in {
     ];
 
     # Use the correct gnome3 packageSet
-    networking.networkmanager.basePackages =
+    networking.networkmanager.basePackages = mkDefault
       { inherit (pkgs) networkmanager modemmanager wpa_supplicant;
         inherit (pkgs.gnome3) networkmanager-openvpn networkmanager-vpnc
                               networkmanager-openconnect networkmanager-fortisslvpn

would need to be done so they'd at least build.

From there we'd probably have to eliminate having to set NIX_GSETTINGS_OVERRIDES_DIR and use #54150. Then make them not conflict.

[wamserma]

#58203 seems also to be related

[jtojnar]

The issues above are fixed but now the conflict occurs in environment.variables.NIX_GSETTINGS_OVERRIDES_DIR. Solution would be #54150

[stale]

Thank you for your contributions.

This has been automatically marked as stale because it has had no activity for 180 days.

If this is still important to you, we ask that you leave a comment below. Your comment can be as simple as "still important to me". This lets people see that at least one person still cares about this. Someone will have to do this at most twice a year if there is no other activity.

Here are suggestions that might help resolve this more quickly:

1. Search for maintainers and people that previously touched the related code and @ mention them in a comment.
2. Ask on the NixOS Discourse.
3. Ask on the #nixos channel on irc.freenode.net.

[romildo]

The issues above are fixed but now the conflict occurs in environment.variables.NIX_GSETTINGS_OVERRIDES_DIR. Solution would be #54150

This is still an issue.

[stale]

I marked this as stale due to inactivity. → More info