Error when using pkg-config in qmake file

Duino

Here is qmake file:

TEMPLATE = app
QT += qml quick widgets
CONFIG += c++11

SOURCES += main.cpp \
    backend.cpp

HEADERS += \
    backend.h

RESOURCES += qml.qrc

INCLUDEPATH +=`pkg-config --cflags opencv`
LIBS += `pkg-config --libs opencv`

#INCLUDEPATH += /usr/local/opencv_itseesz/include
#LIBS += /usr/local/opencv_itseesz/lib/*.so

When using pkg-config tool to find opencv, error occured:

/usr/include/x86_64-linux-gnu/qt5/QtWidgets/qapplication.h:37: error: QtCore/qcoreapplication.h: No such file or directory
 #include <QtCore/qcoreapplication.h>
                                     ^

But when not using the pkg-config, like the two commonted lines below, it worked well.

So, if there is any bugs when using pkg-config in qmake?

BTW, "pkg-config --cflags --libs opencv" works fine in terminal.

Thanks.

tomma

That is not how you use pkg-config with qmake.
Check qmake manual: http://doc.qt.io/qt-5/qmake-project-files.html#configuration-features
You enable pkg-config linking with

CONFIG += link_pkgconfig

and select packages to use with

PKGCONFIG += <package1> <package2>...

Duino

Much thanks!!!