From 050a28f91f4da054c37138f2ed16090da4ee5cac Mon Sep 17 00:00:00 2001
From: fruchti <fruchti@gvfr.de>
Date: Mon, 27 Mar 2023 21:42:08 +0200
Subject: [PATCH] Auto-upgrade: List package differences

---
 options/auto-upgrade.nix | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/options/auto-upgrade.nix b/options/auto-upgrade.nix
index 951b929..a57b468 100644
--- a/options/auto-upgrade.nix
+++ b/options/auto-upgrade.nix
@@ -43,9 +43,11 @@ in
         systemd.services.nixos-upgrade.script = mkOverride 50 (
             let
                 nixos-rebuild = "${config.system.build.nixos-rebuild}/bin/nixos-rebuild";
+                nix-store = "${pkgs.nix}/bin/nix-store";
                 date = "${pkgs.coreutils}/bin/date";
                 readlink = "${pkgs.coreutils}/bin/readlink";
                 grep = "${pkgs.gnugrep}/bin/grep";
+                diff = "${pkgs.diffutils}/bin/diff";
                 git = "${pkgs.git}/bin/git";
                 ssh = "${pkgs.openssh}/bin/ssh";
                 sudo = "${pkgs.sudo}/bin/sudo";
@@ -121,6 +123,18 @@ in
                     email_body="The system upgrade started at $start_time has failed with exit code $exit_code."
                 fi
 
+                echo "→ Determining package differences." | tee -a "$output_file"
+                installed_packages()
+                {
+                    ${nix-store} --query --requisites "$1" | cut -d- -f2- | sort | uniq
+                }
+                current_packages="$(installed_packages /run/current-system)"
+                built_packages="$(installed_packages /nix/var/nix/profiles/system)"
+                ${diff} -y --suppress-common-lines --width=71 \
+                    <(printf "Current generation\n------------------\n%s" "$current_packages") \
+                    <(printf "New generation\n--------------\n%s" "$built_packages") \
+                    | tee -a "$output_file" || true
+
                 booted_version="$(${readlink} /run/booted-system/{initrd,kernel,kernel-modules})"
                 built_version="$(${readlink} /nix/var/nix/profiles/system/{initrd,kernel,kernel-modules})"