nixos/users-groups: Fix the update-lingering activation script failing

The update-lingering activation script currently fails during rebuilds.
This happens when removing a user with linger enabled.
The call to loginctl disable-linger runs for the non-existent user.
This returns an error code which causes the failure.

To mitigate this, this PR removes any residual linger files.
These are files named for the user in /var/lib/systemd/linger.
A simple check for user existence determines whether to delete the file.
This happens before the call to disable-linger to avoid any errors.

Fixes #283769.

1 files changed, 5 insertions, 0 deletions

diff --git a/nixos/modules/config/users-groups.nix b/nixos/modules/config/users-groups.nix
index dd34771c0b42..02cd1a17f538 100644
--- a/nixos/modules/config/users-groups.nix
+++ b/nixos/modules/config/users-groups.nix
@@ -704,6 +704,11 @@ in {
     in stringAfter [ "users" ] ''
       if [ -e ${lingerDir} ] ; then
         cd ${lingerDir}
+        for user in ${lingerDir}/*; do
+          if ! id "$user" >/dev/null 2>&1; then
+            rm --force -- "$user"
+          fi
+        done
         ls ${lingerDir} | sort | comm -3 -1 ${lingeringUsersFile} - | xargs -r ${pkgs.systemd}/bin/loginctl disable-linger
         ls ${lingerDir} | sort | comm -3 -2 ${lingeringUsersFile} - | xargs -r ${pkgs.systemd}/bin/loginctl  enable-linger
       fi