added essentials to darling erasure

modules/darling-erasure/default.nix

@@ -58,4 +58,7 @@
     # we can unmount /mnt and continue on the boot process.
     umount /mnt
   '';
+
+  # In case one forgets to move /etc/shadow to /persist
+  users.users.moritz.initialPassword = "password";
 }

modules/darling-erasure/fs-diff.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+# fs-diff.sh
+set -euo pipefail
+
+OLD_TRANSID=$(sudo btrfs subvolume find-new /mnt/root-blank 9999999)
+OLD_TRANSID=${OLD_TRANSID#transid marker was }
+
+sudo btrfs subvolume find-new "/mnt/root" "$OLD_TRANSID" |
+sed '$d' |
+cut -f17- -d' ' |
+sort |
+uniq |
+while read path; do
+  path="/$path"
+  if [ -L "$path" ]; then
+    : # The path is a symbolic link, so is probably handled by NixOS already
+  elif [ -d "$path" ]; then
+    : # The path is a directory, ignore
+  else
+    echo "$path"
+  fi
+done