Turns out we were experiencing this bug in Unity8, particularly with GTK apps. Just that QtMir will freeze on the last frame and stretch it instead of showing a black window like Mir's compositor does. Also enough GTK windows open smaller than 480x480 by default to have actually worked despite the bug. See bug 1649662 and other duplicates.
Turns out we were experiencing this bug in Unity8, particularly with GTK apps. Just that QtMir will freeze on the last frame and stretch it instead of showing a black window like Mir's compositor does. Also enough GTK windows open smaller than 480x480 by default to have actually worked despite the bug. See bug 1649662 and other duplicates.