From 1353ba26787d398f3595deea28e21a134978df83 Mon Sep 17 00:00:00 2001
From: Peter Hoeg <peter@hoeg.com>
Date: Thu, 4 Oct 2018 11:57:18 +0800
Subject: [PATCH 1/3] system-activation: support script fragments to run in a
 user context

---
 .../system/activation/activation-script.nix   | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/nixos/modules/system/activation/activation-script.nix b/nixos/modules/system/activation/activation-script.nix
index 93a1b13a81d..5a87a2ec762 100644
--- a/nixos/modules/system/activation/activation-script.nix
+++ b/nixos/modules/system/activation/activation-script.nix
@@ -100,6 +100,52 @@ in
             exit $_status
           '';
       };
+    };
+
+    system.userActivationScripts = mkOption {
+      default = {};
+
+      example = literalExample ''
+        { plasmaSetup = {
+            text = '''
+              ${pkgs.libsForQt5.kservice}/bin/kbuildsycoca5"
+            ''';
+            deps = [];
+          };
+        }
+      '';
+
+      description = ''
+        A set of shell script fragments that are executed by a systemd user
+        service when a NixOS system configuration is activated. Examples are
+        rebuilding the .desktop file cache for showing applications in the menu.
+        Since these are executed every time you run
+        <command>nixos-rebuild</command>, it's important that they are
+        idempotent and fast.
+      '';
+
+      type = types.attrsOf types.unspecified;
+
+      apply = set: {
+        script = ''
+          unset PATH
+          for i in ${toString path}; do
+            PATH=$PATH:$i/bin:$i/sbin
+          done
+
+          _status=0
+          trap "_status=1 _localstatus=\$?" ERR
+
+          ${
+            let
+              set' = mapAttrs (n: v: if isString v then noDepEntry v else v) set;
+              withHeadlines = addAttributeName set';
+            in textClosureMap id (withHeadlines) (attrNames withHeadlines)
+          }
+
+          exit $_status
+        '';
+      };
 
     };
 
@@ -177,6 +223,14 @@ in
         source ${config.system.build.earlyMountScript}
       '';
 
+    systemd.user = {
+      services.nixos-activation = {
+        description = "Run user specific NixOS activation";
+        script = config.system.userActivationScripts.script;
+        unitConfig.ConditionUser = "!@system";
+        serviceConfig.Type = "oneshot";
+      };
+    };
   };
 
 }

From 8118d6eb2e34b6f08511819b4e75650cf7f7d9cd Mon Sep 17 00:00:00 2001
From: Peter Hoeg <peter@hoeg.com>
Date: Fri, 5 Oct 2018 10:06:18 +0800
Subject: [PATCH 2/3] switch-to-configuration.pl: activate the
 nixos-activation.service user service

---
 nixos/modules/system/activation/switch-to-configuration.pl | 1 +
 1 file changed, 1 insertion(+)

diff --git a/nixos/modules/system/activation/switch-to-configuration.pl b/nixos/modules/system/activation/switch-to-configuration.pl
index c3e469e4b8a..a9824649e38 100644
--- a/nixos/modules/system/activation/switch-to-configuration.pl
+++ b/nixos/modules/system/activation/switch-to-configuration.pl
@@ -420,6 +420,7 @@ while (my $f = <$listActiveUsers>) {
     print STDERR "reloading user units for $name...\n";
 
     system("su", "-s", "@shell@", "-l", $name, "-c", "XDG_RUNTIME_DIR=/run/user/$uid @systemd@/bin/systemctl --user daemon-reload");
+    system("su", "-s", "@shell@", "-l", $name, "-c", "XDG_RUNTIME_DIR=/run/user/$uid @systemd@/bin/systemctl --user start nixos-activation.service");
 }
 
 close $listActiveUsers;

From 4dada63a174331151251cf8be093cd8fcdf28c12 Mon Sep 17 00:00:00 2001
From: Peter Hoeg <peter@hoeg.com>
Date: Thu, 4 Oct 2018 11:57:55 +0800
Subject: [PATCH 3/3] plasma5: run kbuildsycoca5 in the user context

---
 nixos/modules/services/x11/desktop-managers/plasma5.nix | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/nixos/modules/services/x11/desktop-managers/plasma5.nix b/nixos/modules/services/x11/desktop-managers/plasma5.nix
index e759f69db89..70655592145 100644
--- a/nixos/modules/services/x11/desktop-managers/plasma5.nix
+++ b/nixos/modules/services/x11/desktop-managers/plasma5.nix
@@ -225,11 +225,8 @@ in
       security.pam.services.sddm.enableKwallet = true;
       security.pam.services.slim.enableKwallet = true;
 
-      # Update the start menu for each user that has `isNormalUser` set.
-      system.activationScripts.plasmaSetup = stringAfter [ "users" "groups" ]
-        (concatStringsSep "\n"
-          (mapAttrsToList (name: value: "${pkgs.su}/bin/su ${name} -c ${pkgs.libsForQt5.kservice}/bin/kbuildsycoca5")
-            (filterAttrs (n: v: v.isNormalUser) config.users.users)));
+      # Update the start menu for each user that is currently logged in
+      system.userActivationScripts.plasmaSetup = "${pkgs.libsForQt5.kservice}/bin/kbuildsycoca5";
     })
   ];