From 602e14fc8bc7d7acc5b99687de2ecc7d23da4201 Mon Sep 17 00:00:00 2001
From: worldofpeace <worldofpeace@protonmail.ch>
Date: Wed, 6 Nov 2019 15:05:22 -0500
Subject: [PATCH 1/2] gnome3.gnome-flashback: add systemd targets for
 customSessions

---
 pkgs/desktops/gnome-3/misc/gnome-flashback/default.nix | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/pkgs/desktops/gnome-3/misc/gnome-flashback/default.nix b/pkgs/desktops/gnome-3/misc/gnome-flashback/default.nix
index e381860ca2c9..dc7e0ed222f0 100644
--- a/pkgs/desktops/gnome-3/misc/gnome-flashback/default.nix
+++ b/pkgs/desktops/gnome-3/misc/gnome-flashback/default.nix
@@ -22,6 +22,7 @@
 , writeTextFile
 , writeShellScriptBin
 , xkeyboard_config
+, runCommand
 }:
 
 let
@@ -141,6 +142,13 @@ let
           DesktopNames=GNOME-Flashback;GNOME;
         '';
       };
+
+      mkSystemdTargetForWm = { wmName }:
+        runCommand "gnome-flashback-${wmName}.target" {} ''
+          mkdir -p $out/lib/systemd/user
+          cp "${gnome-flashback}/lib/systemd/user/gnome-session-x11@gnome-flashback-metacity.target" \
+            "$out/lib/systemd/user/gnome-session-x11@gnome-flashback-${wmName}.target"
+        '';
     };
 
     meta = with stdenv.lib; {

From 473cd0d4ba97a579b473c37022a5809af3b6b76f Mon Sep 17 00:00:00 2001
From: worldofpeace <worldofpeace@protonmail.ch>
Date: Wed, 6 Nov 2019 15:14:25 -0500
Subject: [PATCH 2/2] nixos/gnome3: add gnome-flashback to systemd.packages

When we did the revert of adding gnome-flashback to systemd.packages [0]
I forgot to test with other display managers. If we use GDM with gnome-flashback
it appears it doesn't try to fallback to non-systemd startup and always fails and
starts the regular gnome-session. So adding gnome-flashback to systemd.packages
was perfectly fine, but we did forgot one detail. We need systemd targets for the
customSessions which is added using  mkSystemdTargetForWm in the gnome-
flashback package.

[0]: 42f567b30def552337bf17a6d30410c16c2b47cc
---
 nixos/modules/services/x11/desktop-managers/gnome3.nix | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/nixos/modules/services/x11/desktop-managers/gnome3.nix b/nixos/modules/services/x11/desktop-managers/gnome3.nix
index 5ad31e5b9d00..7338319f1115 100644
--- a/nixos/modules/services/x11/desktop-managers/gnome3.nix
+++ b/nixos/modules/services/x11/desktop-managers/gnome3.nix
@@ -184,6 +184,13 @@ in
         enableGnomeKeyring = true;
       };
 
+      systemd.packages = with pkgs.gnome3; [
+        gnome-flashback
+      ] ++ (map
+        (wm: gnome-flashback.mkSystemdTargetForWm {
+          inherit (wm) wmName;
+        }) cfg.flashback.customSessions);
+
       services.dbus.packages = [
         pkgs.gnome3.gnome-screensaver
       ];