Gnome Flashback Error while upgrading to 21.05

[tyrion]

I am trying to upgrade to 21.05 from 20.09 and I cannot build the system because of a gnome-flashback error.

The relevant part of my configuration.nix is the following:

{ config, lib, pkgs, ... }:
{
  services.gnome.gnome-keyring.enable = true;
  services.xserver = {
    enable = true;
    exportConfiguration = true; # export configuration to /etc/X11/xorg.conf
    layout = "us";
    xkbOptions = lib.mkDefault "eurosign:e, caps:swapescape, compose:ralt";
    desktopManager = {
      xterm.enable = false;
      gnome = {
        enable = true;
        flashback.customSessions = [
          {
            wmCommand = "${pkgs.i3-gaps}/bin/i3";
            wmLabel = "i3";
            wmName = "i3";
          }
        ];
      };
    };
    displayManager = {
      defaultSession = lib.mkDefault "gnome-flashback-i3"; # xfce+i3
      autoLogin = {
        enable = true;
        user = "tyrion";
      };
      gdm = {
        enable = true;
      };
    };
    windowManager.i3 = {
      enable = true;
      package = pkgs.i3-gaps;
      extraPackages = with pkgs; [
        arandr
        rofi
        dmenu
        i3status
        polybarFull
        i3lock-fancy
      ];
      extraSessionCommands = ''
        ${pkgs.xorg.xsetroot}/bin/xsetroot -solid black
      '';
    };
  };
  programs.seahorse.enable = true;
}

Here is the error I get:

gnome-flashback-i3.target> cp: cannot stat '/nix/store/gp9vdsykwybvpiay3syay1m97n3vv4ym-gnome-flashback-3.40.0/lib/systemd/user/[email protected]': No such file or directory
error: --- Error --- build-remote
build of '/nix/store/wv1vaawm9cwrb6kpmhka55ms2s3hi8vr-gnome-flashback-i3.target.drv' on 'ssh://tyrion@***' failed: error: --- Error --- nix-daemon
builder for '/nix/store/wv1vaawm9cwrb6kpmhka55ms2s3hi8vr-gnome-flashback-i3.target.drv' failed with exit code 1; last 1 log lines:
  cp: cannot stat '/nix/store/gp9vdsykwybvpiay3syay1m97n3vv4ym-gnome-flashback-3.40.0/lib/systemd/user/[email protected]': No such file or directory
error: --- Error ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ nix
builder for '/nix/store/wv1vaawm9cwrb6kpmhka55ms2s3hi8vr-gnome-flashback-i3.target.drv' failed with exit code 1
error: --- Error ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ nix
1 dependencies of derivation '/nix/store/c11dgmyc3ah7cjqhnkani4rxyc8a4p1i-system-generators.drv' failed to build
error: --- Error ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ nix
1 dependencies of derivation '/nix/store/hxb0zc1n0md59lw039202klanlsdmcj1-etc.drv' failed to build

Unfortunately, I am not sure how to provide more reproducible steps. I tried to understand what was the problem but couldn't do it quickly, so meanwhile I am opening this issue.

[gazally]

I encountered this yesterday. Setting services.xserver.desktopManager.gnome.flashback.customSessions in 21.05 causes the build to fail. I made this patch which got my system up and running:

diff --git a/pkgs/desktops/gnome/misc/gnome-flashback/default.nix b/pkgs/desktops/gnome/misc/gnome-flashback/default.nix
index 7e578f27cd2..a431b1e33fc 100644
--- a/pkgs/desktops/gnome/misc/gnome-flashback/default.nix
+++ b/pkgs/desktops/gnome/misc/gnome-flashback/default.nix
@@ -186,8 +186,8 @@ let
       mkSystemdTargetForWm = { wmName }:
         runCommand "gnome-flashback-${wmName}.target" { } ''
           mkdir -p $out/lib/systemd/user
-          cp "${gnome-flashback}/lib/systemd/user/[email protected]" \
-            "$out/lib/systemd/user/gnome-session-x11@gnome-flashback-${wmName}.target"
+          cp -r "${gnome-flashback}/lib/systemd/user/[email protected]" \
+            "$out/lib/systemd/user/gnome-session@gnome-flashback-${wmName}.target.d"
         '';
     };
 

Today when I looked into making my patch into a PR, I realized that this change was already made in master by #113957. Can that PR be backported to 21.05?

@chpatrick @jtojnar

[chpatrick]

@jtojnar do you think we should backport my PR wholesale to 21.05? It shouldn't break any existing setups, but it would fix this issue and also make the default applets available. We would also want your follow-up commit b2f86e6.

[jtojnar]

Ideally, we would only backport the fix since there are new extra restrictions on the desktop file names but that would probably be too much effort. If someone wants to open a backport PR, feel free.

[chpatrick]

Those restrictions are also good though, since it doesn't work if you have an invalid filename.

[stale]

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

[patka-123]

Hello @tyrion 👋

Since 21.05 is no longer supported and this doesn't seem to be an issue for current nixos versions, would you be able to close this issue?

(I'm going through issues marked as stale to see what can be resolved. If this is still an issue you experience then don't mind me).