当UseCommandProcessor设置为True时，MSBuild Exec失败

Question

我定义了一个目标来调用exec

<Target Name="BuildInstaller" >    
     <Exec Command="attrib -R /S /D $(MSBuildProjectDirectory)\Environment\Installer\ServicePlatform\*.*" />    
     <Exec Command="dir *.* /s" />  
</Target>

它完美无缺

但是如果我将UseCommandProcessor设置为True

     <Target Name="BuildInstaller" >    
         <Exec Command="attrib -R /S /D $(MSBuildProjectDirectory)\Environment\Installer\ServicePlatform\*.*" />    
         <Exec Command="dir *.* /s" UseCommandProcessor="True"/>  
    </Target>

我明白了：

c:\Dev>/Q /C:\Users\MyUser\AppData\Local\Temp\tmp63250fcf10714224b92eeeb09e25b6f5.exec.cmd
'/Q' is not recognized as an internal or external command, operable program or batch file.

为什么会这样？我做错了什么？