When /usr is placed on separate partition that by some reason cannot be mounted (I've moved /usr to SquashFS and missed just one thing), Qingy won't run because it's qingy.so library is installed to /usr/lib64 and is not accessible.
This way I couldn't even boot to a single user mode (yes, I've forgot that I had agetty running on some tty faraway).
I suggest moving qingy.so to /lib since it'll be consistent with placing qingy binary to /sbin and will allow booting to single user mode without /usr mounted (just as with agetty).
Created attachment 370716 [details, diff]
Patch that fixes the problem