Comment 1 for bug 1221414

I can confirm this. I tried with nik90's branch:
https://code.launchpad.net/~nik90/ubuntu-clock-app/add-hud-support

simply branch it, open with QtCreator and do Build -> Ubuntu Touch -> Run Application on Device

Naturally the actions don't end up to the HUD as the app is unable to access the session bus.

The other thing I see is that it seems that QtC does not set the $APP_ID env variable:
phablet 22127 1.8 7.2 195016 51592 ? Ssl 19:26 0:05 /usr/lib/arm-linux-gnueabihf/qt5/bin/qmlscene /home/phablet/dev_tmp/add-hud-support/ubuntu-clock-app.qml --desktop_file_hint=/home/phablet/.local/share/applications/ubuntu-clock-app.desktop

The proper launch command should be:
APP_ID=ubuntu-clock-app /usr/lib/arm-linux-gnueabihf/qt5/bin/qmlscene /home/phablet/dev_tmp/add-hud-support/ubuntu-clock-app.qml --desktop_file_hint=/home/phablet/.local/share/applications/ubuntu-clock-app.desktop