Comment # 5 on bug 101055 from Rutger van Bergen

I think this may relate to the problem described in this bug:
https://bugs.freedesktop.org/show_bug.cgi?id=100189. It states there that the
i915 Gallium driver is unmaintained, and may be removed from a future version
of Mesa. 

In any case, I am running into exactly the same problem, which exposes itself
by sddm-greeter crashing on startup, after a recent upgrade to  Mesa 17.1.10.