script = ''
set -e
+
+ # Chill for awhile before applying updates. If applying an update
+ # badly breaks things, we want a window in which an operator can
+ # intervene either to fix the problem or disable automatic updates.
+ sleep 2h
+
(
cd /etc/nixos
${pkgs.keyedgit cfg.key}/bin/git pull --ff-only --verify-signatures