Created attachment 208597 [details]
adding mesa-dri dependency explicitly.
A user of the calibre port is launching calibre from a remote machine where he is not installing the full Xorg stack, but only calibre and it's direct dependencies.
He reported in bug #241485 that in this setup the calibre ebook-reader component fails to start properly. Installing mesa-dri fixed the issue for him, letting the calibre component find the swrast driver it was needing.
I have reproduced his findings using to VirtualBox VMs, so I guessed qt5-gui is the port whose libraries are actually making the GL calls depending on the mesa-dri drivers.
As a side note my machine has an nvidia card and in this combination things don't work anyway, I guess that's because the nvidia dirver overrides libGL and friends.
Do you think it is correct to add this run time dependency? For most users installing qt5 on the machine together with the Xserver this is a noop. It could help in other situations.
Thinking again about it, I suspect the dependency should be added to mesa-libs or through USES=gl.
Any thought about this?