qmake -tp vc generates extra folders

Unzip the attached test application e.g. under D:\. You will get a following folder structure:

D:\testapp_subdir
D:\testapp_subdir\build (empty folder)
D:\testapp_subdir\src\testapp_all.pro (defines only SUBDIRS += core)
D:\testapp_subdir\src\core\core.pro
--> core.pro defines a simple 'app' and MOC_DIR, RCC_DIR and UI_DIR paths:
MOC_DIR= ../../build/moc
RCC_DIR= ../../build/rcc
UI_DIR= ../../build/uic

Open Visual studio command prompt (VS2010 used during testing), go to folder D:\testapp_dir\build (which is currently empty) and type command: qmake -tp vc -r ../src/testapp_all.pro

Error: extra 'build' folders appears under D:\ (i.e. on the same folder level where the 'testapp_subdir' is located):

D:\build
D:\build\moc (empty folder)
D:\build\rcc (empty folder)
D:\build\uic (empty folder)