在大文件夹执行clear up的情况下，有的时候会出现递归任务死循环，提示：

Clearup failed to process the following paths:
D:\xxx\xxx
Previous operation has not finished; run 'clearup' if it was interrupted
Please execute the 'Clearup' command.

此时无论等多久乃至重启电脑都clearup不了，可以用sqlite3.exe这个工具，删除svn的队列。双击sqlite3.exe之后，执行下面两个命令：

D:\xxx\xxx\sqlite3 .svn/wc.db "select * from work_queue"
D:\xxx\xxx\sqlite3 .svn/wc.db "delete from work_queue"

sqlite3.exe 自行查找咯