anchor.diff:              rm -f "$authfile"
               authKeys="${marker2},$authKeys"
             else
  -            ${pkgs.gnused}/bin/sed -i '/^### NixOS.*$/,$d' "$authfile"
  -            authKeys="${marker1},$authKeys"
  +            ${pkgs.gnused}/bin/sed -i '/${marker1}/ d' "$authfile"
             fi
             for key in $authKeys; do ${pkgs.coreutils}/bin/echo "$key" >> "$authfile"; done
           fi
  
positive.code: 
          for f in $authKeyFiles; do
            if [ -f "$f" ]; then
              authKeys="$(${pkgs.coreutils}/bin/cat "$f"),$authKeys"
            fi
          done
  
  
negative.code: 
    mkAuthkeyScript =
      let
        marker1 = "### NixOS auto-added key. Do not edit!";
        marker2 = "### NixOS will regenerate this file. Do not edit!";
        users = map (userName: getAttr userName config.users.extraUsers) (attrNames config.users.extraUsers);
        usersWithKeys = flip filter users (u:
  