From 9fb9ed110c1aaf6e40806c9173a15b490e49faff Mon Sep 17 00:00:00 2001
From: Artturin <Artturin@artturin.com>
Date: Fri, 24 Dec 2021 16:44:27 +0200
Subject: [PATCH] nixos/systemd: disable systemd-gpt-auto-generator by default

---
 .../doc/manual/from_md/release-notes/rl-2205.section.xml  | 8 ++++++++
 nixos/doc/manual/release-notes/rl-2205.section.md         | 2 ++
 nixos/modules/system/boot/systemd.nix                     | 6 ++++--
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
index 4d3d5700ffca1..1ece055d53799 100644
--- a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
+++ b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
@@ -117,6 +117,14 @@
           <literal>virtualisation.docker.daemon.settings</literal>.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          <literal>systemd-gpt-auto-generator</literal> is now disabled
+          by default due to conflicting with our declarative mount
+          management, Issue
+          <link xlink:href="https://github.com/NixOS/nixpkgs/issues/4002">#4002</link>.
+        </para>
+      </listitem>
     </itemizedlist>
   </section>
   <section xml:id="sec-release-22.05-notable-changes">
diff --git a/nixos/doc/manual/release-notes/rl-2205.section.md b/nixos/doc/manual/release-notes/rl-2205.section.md
index 966de78893738..9928c95f7370d 100644
--- a/nixos/doc/manual/release-notes/rl-2205.section.md
+++ b/nixos/doc/manual/release-notes/rl-2205.section.md
@@ -43,6 +43,8 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - If you previously used `/etc/docker/daemon.json`, you need to incorporate the changes into the new option `virtualisation.docker.daemon.settings`.
 
+- `systemd-gpt-auto-generator` is now disabled by default due to conflicting with our declarative mount management, Issue [#4002](https://github.com/NixOS/nixpkgs/issues/4002).
+
 ## Other Notable Changes {#sec-release-22.05-notable-changes}
 
 - The option [services.redis.servers](#opt-services.redis.servers) was added
diff --git a/nixos/modules/system/boot/systemd.nix b/nixos/modules/system/boot/systemd.nix
index ec5dea075bbce..27c7466ac463f 100644
--- a/nixos/modules/system/boot/systemd.nix
+++ b/nixos/modules/system/boot/systemd.nix
@@ -512,12 +512,14 @@ in
     systemd.generators = mkOption {
       type = types.attrsOf types.path;
       default = {};
-      example = { systemd-gpt-auto-generator = "/dev/null"; };
+      example = literalExpression ''{ systemd-gpt-auto-generator = "${config.systemd.package}/lib/systemd/system-generators/systemd-gpt-auto-generator"; };'';
       description = ''
         Definition of systemd generators.
         For each <literal>NAME = VALUE</literal> pair of the attrSet, a link is generated from
         <literal>/etc/systemd/system-generators/NAME</literal> to <literal>VALUE</literal>.
+        Note: systemd-gpt-auto-generator is disabled by default due to not being declarative.
       '';
+        # systemd-gpt-auto-generator issue https://github.com/NixOS/nixpkgs/issues/4002
     };
 
     systemd.shutdown = mkOption {
@@ -1053,7 +1055,7 @@ in
         '') config.system.build.etc.passthru.targets;
       }) + "/*";
 
-      "systemd/system-generators" = { source = hooks "generators" cfg.generators; };
+      "systemd/system-generators" = { source = hooks "generators" ({ systemd-gpt-auto-generator = "/dev/null"; } // cfg.generators); };
       "systemd/system-shutdown" = { source = hooks "shutdown" cfg.shutdown; };
     });