The input_qr_from_screenshot functionality is broken on some Linux machines:
on some machines, `screen.grabWindow(0)` returns an all-black image.
In such cases, instead of telling the user "No QR code was found on the screen",
we will tell them "Failed to take screenshot".
To test:
`QApplication.instance().primaryScreen().grabWindow(0).save("/home/user/wspace/tmp/pic2.png", "png")`
Tested on:
- machine 1:
- ubuntu 22.04, gnome, wayland
- pyqt.version: 5.15.9
- qt.version: 5.15.2
=> gets all-black image for screenshot
- machine 2:
- manjaro, kde, x11
- pyqt.version: 5.15.9
- qt.version: 5.15.8
=> screenshot works
I guess it might be due to x11 vs wayland.
635880b3cb