Code review comment for lp:~robru/webbrowser-app/packaging

So, I installed libhud-qt-qml from the PPA, and then I was able to install this package. It doesn't run though:

$ webbrowser-app

WARNING: This project is using the experimental QML API extensions for QtWebKit and is therefore tied to a specific QtWebKit release.
WARNING: The experimental API will change from version to version, or even be removed. You have been warned!

register types Ubuntu.HUD
initialize engine Ubuntu.HUD
file:///usr/lib/x86_64-linux-gnu/qt5/qml/Ubuntu/Browser/Browser.qml:130:22: Cannot assign to non-existent property "devicePixelRatio"
             experimental.devicePixelRatio: browser.qtwebkitdpr
                          ^
Segmentation fault (core dumped)

Thoughts, Olivier? I'm not good with gdb so I'll need you to guide me somewhat to better troubleshoot this.