Comment 4 for bug 1580981

Timo already nicely summed up our discussion :)

I will leave my investigation here just for completeness:
the fix applies to the "device" mkspec, which is the one (I guess) that is used when building using QtCreator with an ARM device target.

So it "should" fix that usecase (not tested).

What it doesn't fix, is the usecase where you directly enter an arm chroot for crosscompilation purposes without using QtCreator. In that case the compilation goes through ubuntu-arm-gnueabihf-g++ makespec which is missing the correct PKGCONFIG path redirection that is done by https://codereview.qt-project.org/#/c/143276/2//ALL,unified