vc编译时为什么会出cl错误?
--------------------Configuration: ttt - Win32 Debug--------------------
Compiling...
ttt.cpp
e:\ttt\ttt.cpp(4) : fatal error C1083: Cannot open precompiled header file: 'Debug/ttt.pch': No such file or directory
Error executing cl.exe.
^^^^^^
ttt.obj - 1 error(s), 0 warning(s)
以上是错误例子 why?