cornerstone出错经常是因为缓存的问题造成了，今天介绍下cornerstone清除缓存的方法。
1. Quit Cornerstone
2. Open Terminal
3. Copy paste the following line into Terminal:
defaults delete com.zennaware.Cornerstone HistoryCacheUsage
4. Press return
5. Open Finder
6. Select Go->Go To Folder…
7. Enter:
~/Library/Caches/Cornerstone
and click “Go”
8. Move the selected directory (“Cornerstone”) to the Trash.
9. Restart Cornerstone
The next time Cornerstone prompts you to cache the repository log, choose “Never”.
