> [...]
> And vlc fails to build due to can't find headers of Qt5X11Extras.
> Indeed, the pkg-config output of Qt5X11Extras seems wrong:

> $ pkg-config --cflags --libs Qt5X11Extras
> -I/gnu/store/l8xp2i57plmdd3pprhznc8r03ha3sv2s-qtbase-5.9.1/include/qt5/QtGui -I/gnu/store/l8xp2i57plmdd3pprhznc8r03ha3sv2s-qtbase-5.9.1/include/qt5 -I/gnu/store/l8xp2i57plmdd3pprhznc8r03ha3sv2s-qtbase-5.9.1/include/qt5/QtCore -I/gnu/store/l8xp2i57plmdd3pprhznc8r03ha3sv2s-qtbase-5.9.1/include/qt5 -I/gnu/store/l8xp2i57plmdd3pprhznc8r03ha3sv2s-qtbase-5.9.1/include/qt5/QtX11Extras -I/gnu/store/l8xp2i57plmdd3pprhznc8r03ha3sv2s-qtbase-5.9.1/include/qt5 -L/gnu/store/l8xp2i57plmdd3pprhznc8r03ha3sv2s-qtbase-5.9.1/lib -lQt5X11Extras -lQt5Gui -lQt5Core

> I can try fix this pkg-config issue.

Here is it: