Comment 7 for bug 1492778

I forgot to add:
in my tracing of libqxcb, I found that this library conflates screens with outputs.
When there are no more Outputs connected,
it returns 0 screens.

Traditionally an X screen could exist independently of its outputs.

The actual packages that will need to work to fix this very important issue are:

          libqxcb (Qt5)
          xserver-xorg-video-intel (or intel graphics driver)
          xrandr

Patching libqxcb is not enough. The crash happens later in the chain of events if so (I tried and tried).
It seems plasma and Qt5 cannot function without outputs. Other graphic environments "solve" this by always providing at least one mock or virtual output, when all physical monitors have been unplugged or asserted HotPlug pin 19 of HDMI.

--Juan Manuel Cabo