[Qt-interest] How to build a profile for some subdirectories?

[Kermit Mei]

Hello community!

My project's library directory is like this:

$ pwd
/home/ect/apptest/lib

$ tree -L 1
.
|-- Audio
|-- Menu
|-- ThirdParty
|-- Effect
|-- Photo
`-- Upgrade

All the six subdirectories are independence, they have their own .pro
project file, and they can pass the compile.

But, everytime I want to update the libs, I must enter all the
subdirectory to compile the libs. I want to find  out the way that I can
only run "qmake" under lib (their parent directory), and then qmake can
find out the six profiles under the subdirectories. 

How to write that .pro file?

Thanks

Kermit Mei