Install Trebuchet in Oxygen OS?

Has anyone been able to install trebuchet on oxygen os? it gives me error!

[Q] How to set wallpaper on lockscreen in Trebuchet/ CM

I recently installed CM12.1 and using Trebuchet as my launcher. I have checked around and cannot seem to find where to configure the wallpaper for the Lock Screen. Changing the theme changes it, but i cannot seem to find where in the settings to change it.