Tilix-quake fails to start tilix on Gnome Shell 3.32: Main.Util is undefined

Importing

const Util = imports.misc.util;

and changing

Main.Util.trySpawnCommandLine("env GDK_BACKEND=x11 tilix --quake");

into

Util.trySpawnCommandLine("env GDK_BACKEND=x11 tilix --quake");

fixed it for me.