只是mac 版的问题, pc朋友可以略过
以前都试过，但就不知到什麼事当掉，现在知到了！查清楚原来有一个这样的bug，这个command-z 的bug，很容易发生在zap spell 按shift-z 错手的时候。虽然mac 有time machine ，不过因为running game 的时候nethack程序是会删掉save file 的，当掉的话进度会全没了，真想X爆他啊！
我真的很不喜欢它run game 就删掉存档的做法，一当就完蛋，就算不希望人不停地reload game，都用不著del save 这麼大动作的！人家diablo ii 都不会做这种事。有心人要copy这个file去reload 都好容易，尤其是mac 版. del save 这做法很要不得，是会害死正经玩的玩家.
其实是可以用以下的做法：去到某些常到的地方例如altar，或者常做的动作好像pray、上落楼梯以及drop item to altar，就autosave，抄写一个一百多K的file，在这些动作发生时，不会太过拖慢游戏的，这样就ok了！nethack 的档案是很小，但它玩起来就不是小游戏，不能这样搞的......


查到下面的文件的时候，以经quit 以及没了存档，XXX！
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M343-4   Open   In the Qt port, Command-Z crashes the game and prevents it from restarting.   Recovery instructions.  
Recovery instructions for MacOS X Qt port - when the game refuses to start orhas crashed.
THESE INSTRUCTIONS ASSUME YOU HAVE INSTALLED THE DMG PACKAGE RELEASED INOCTOBER 2009.
If you are running the older .tgz package, see the "MANUALRECOVERY INSTRUCTIONS" farther down this page.
1) Use the Finder to locate "NetHackQt", but DO NOT try to start the game.
2) Hold down the control key and click on "NetHackQt" - select "Show Package Contents"
3) Double click on "nethackdir"
4) Double click on "NetHackRecover" and follow the on-screen instructions.
5) If recover was able to save the game that was in progress when NetHackQt crashed or was Force Quit, the next time the game starts it will restore the game.
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MANUAL RECOVERY INSTRUCTIONS
These instructions assume you are comfortable using Terminal.app and thecommand line. If you are not, now might be a good time to reinstall thegame using the new .dmg package instead.
1) cd into NetHack.app. The path depends on where you installed NetHack originally.
2) cd nethackdir
3) rm perm_lock This file may not exist; that is not a problem.
4) See if there is a game to recover. If there are files named with a number (your uid) followed by your Unix user name, there is. (Hint: use the "id" command to find this information.)
To attempt recovery of the game, enter this command, substituting as appropriate:./recover -d .
for example:./recover -d . 604shelly

以下连结是pc 的存档方式, 做个记录
https://tieba.baidu.com/f?kz=1005748730