[PATCH v2 2/8] host/rootfs: Install systemd-pull

[Demi Marie Obenour <demiobenour@gmail.com>]

Due to a systemd bug [1], building systemd-sysupdate does not require
that systemd-pull is built as well.  However, systemd-sysupdate has a
run-time dependency on systemd-pull.  Therefore, override the systemd
derivation so that systemd-pull is built.  Confusingly, this requires
enabling systemd-importd.

If systemd-pull or systemd-sysupdate is not built, the resulting image
will be broken and users will not be able to recover without either a
reinstall or reverting to the previous version.  Therefore, add a check
to ensure that both are in fact built.  Use 'cat' rather than just
'stat' to catch broken symlinks and the like.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
---
 host/rootfs/default.nix | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/host/rootfs/default.nix b/host/rootfs/default.nix
index aea2e46bb5998176eb6d9b8aef802ae270fdd28c..c2045ad96cca37a1bf1a7b82aa35a583cc5aee93 100644
--- a/host/rootfs/default.nix
+++ b/host/rootfs/default.nix
@@ -43,7 +43,8 @@ let
     })
 
   # Take kmod from pkgsGui since we use pkgsGui.kmod.lib below anyway.
-  ] ++ (with pkgsGui; [ cosmic-files crosvm foot fuse3 kmod systemd ]);
+  ] ++ (with pkgsGui; [ cosmic-files crosvm foot fuse3 kmod ]);
+
 
   nixosAllHardware = nixos ({ modulesPath, ... }: {
     imports = [ (modulesPath + "/profiles/all-hardware.nix") ];
@@ -64,7 +65,15 @@ let
   # https://inbox.vuxu.org/musl/20251017-dlopen-use-rpath-of-caller-dso-v1-1-46c69eda1473@iscas.ac.cn/
   usrPackages = [
     appvm kernel.modules firmware netvm
-  ] ++ (with pkgsGui; [ dejavu_fonts kmod.lib mesa westonLite ]);
+  ] ++ (with pkgsGui; [
+    dejavu_fonts kmod.lib mesa westonLite
+    # Work around NixOS/nixpkgs#459020: without "withImportd = true"
+    # systemd-pull doesn't get built, so systemd-sysupdate doesn't work.
+    (systemd.override {
+      withImportd = true;
+      withSysupdate = true;
+    })
+  ]);
 
   appvms = {
     appvm-firefox = callSpectrumPackage ../../vm/app/firefox.nix {};
@@ -85,6 +94,16 @@ let
         lndir -ignorelinks -silent "$pkg" "$out/usr"
     done
 
+    # If systemd-pull is missing systemd-sysupdate will fail with a
+    # very confusing error message.  If systemd-sysupdate doesn't work,
+    # users will not be able to receive an update that fixes the problem.
+    for i in sysupdate pull; do
+        if ! cat -- "$out/usr/lib/systemd/systemd-$i" > /dev/null; then
+            echo "link to systemd-$i didn't get installed" >&2
+            exit 1
+        fi
+    done
+
     # Weston doesn't support SVG icons.
     inkscape -w 20 -h 20 \
         -o $out/usr/share/icons/hicolor/20x20/apps/com.system76.CosmicFiles.png \

-- 
2.51.2