Rendering tens of minutes of empty timeline when "Use GPU processing (Movit library)" is checked

If "Use GPU processing (Movit library)" is checked in the Playback settings - no matter what encoder one uses or if the Full project or Selected zone only were selected in the Rendering dialogue - output file will contain whole project plus about 16 minutes of black screen. Curiously, rendering time is like there were real content processing.

Apparently, I'm not only one affected by this. https://forum.kde.org/viewtopic.php?f=272&t=160722

Checked on OpenSUSE Tumbleweed, kdenlive 19.04.1-1.2 with libmovit8 1.6.2-1.4 and kdenlive 19.07.70git.20190601T081229 with libmovit8 1.6.2-30.14

As soon as this option is unchecked and kdenlive relaunched - everything works smoothly.